Filed Pursuant to Rule 497
Registration No. 333-224281

PROSPECTUS SUPPLEMENT

(To prospectus dated June 5, 2018)

6,000,000 Shares

Common Stock

We are offering 6,000,000 shares of our common stock. Our common stock is listed on the New York Stock Exchange, or the NYSE, under the trading symbol “HTGC.” The last sale price, as reported on the NYSE on June 7, 2018, was $12.34 per share. The net asset value per share of our common stock at March 31, 2018 (the last date prior to the date of this prospectus supplement on which we determined net asset value) was $9.72.

We are an internally-managed, non-diversified, closed-end investment company that has elected to be regulated as a business development company under the Investment Company Act of 1940, as amended, or the 1940 Act. Our investment objective is to maximize our portfolio’s total return by generating current income from our debt investments and capital appreciation from our warrant and equity-related investments.

An investment in our common stock involves risks that are described in the “Risk Factors” section beginning on page 14 of the accompanying prospectus.

This prospectus supplement and the accompanying prospectus contain important information you should know before investing in our common stock. Please read this prospectus supplement and the accompanying prospectus before investing and keep it for future reference. We file annual, quarterly and current reports, proxy statements and other information about us with the Securities and Exchange Commission. This information is available free of charge by contacting us at 400 Hamilton Avenue, Suite 310, Palo Alto, California 94301, or by telephone by calling collect at (650) 289-3060 or on our website at www.htgc.com. The information on the websites referred to herein is not incorporated by reference into this prospectus supplement or the accompanying prospectus. The SEC also maintains a website at www.sec.gov that contains information about us.

The underwriters may also purchase up to an additional 900,000 shares from us at the public offering price, less the underwriting discounts and commissions, to cover overallotments, if any, within 30 days of the date of this prospectus supplement. If the underwriters exercise this option in full, the total public offering price will be $83,835,000, the total sales load (underwriting discounts and commissions) paid by us will be $2,553,000, and total proceeds, before expenses, will be $81,282,000.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Delivery of the shares of common stock will be made on or about June 14, 2018.

Joint Book-Running Managers

Lead Manager

Compass Point

The date of this prospectus supplement is June 12, 2018.

You should rely only on the information contained in this prospectus supplement and the accompanying prospectus. We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information contained in this prospectus supplement and the accompanying prospectus is accurate only as of the date on the front cover of this prospectus supplement or such prospectus, as applicable. Our business, financial condition, results of operations and prospects may have changed since that date.

This document is in two parts. The first part is this prospectus supplement, which describes the terms of this offering and also adds to and updates information contained in the accompanying prospectus. The second part is the accompanying prospectus, which gives more general information and disclosure. To the extent the information contained in this prospectus supplement differs from the information contained in the accompanying prospectus, the information in this prospectus supplement shall control. You should read this prospectus supplement and the accompanying prospectus together with the additional information described under the heading, “Available Information” before investing in our common stock.

TABLE OF CONTENTS

Prospectus Supplement

Prospectus

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FEES AND EXPENSES

The following table is intended to assist you in understanding the various costs and expenses that an investor in our common stock will bear directly or indirectly, assuming that the underwriters do not exercise their over-allotment option. However, we caution you that some of the percentages indicated in the table below are estimates and may vary. The footnotes to the fee table state which items are estimates. Except where the context suggests otherwise, whenever this prospectus contains a reference to fees or expenses paid by “you” or “us” or that “we” will pay fees or expenses, stockholders will indirectly bear such fees or expenses as investors in Hercules Capital, Inc.

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Example

The following example demonstrates the projected dollar amount of total cumulative expenses that would be incurred over various periods with respect to a hypothetical investment in our common stock. These amounts are based upon our payment of annual operating expenses at the levels set forth in the table above and assume no additional leverage.

The example and the expenses in the tables above should not be considered a representation of our future expenses, and actual expenses may be greater or lesser than those shown. Moreover, while the example assumes, as required by the applicable rules of the SEC, a 5% annual return, our performance will vary and may result in a return greater or lesser than 5%. In addition, while the example assumes reinvestment of all distributions at net asset value (“NAV”), participants in our dividend reinvestment plan may receive shares valued at the market price in effect at that time. This price may be at, above or below NAV. See “Dividend Reinvestment Plan” in the accompanying prospectus for additional information regarding our dividend reinvestment plan.

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FORWARD-LOOKING STATEMENTS

The matters discussed in this prospectus supplement and the accompanying prospectus, as well as in future oral and written statements by management of Hercules Capital, Inc. that are forward-looking statements are based on current management expectations that involve substantial risks and uncertainties which could cause actual results to differ materially from the results expressed in, or implied by, these forward-looking statements. Forward-looking statements relate to future events or our future financial performance. We generally identify forward-looking statements by terminology such as “may,” “will,” “should,” “expects,” “plans,” “anticipates,” “could,” “intends,” “target,” “projects,” “contemplates,” “believes,” “estimates,” “predicts,” “potential” or “continue” or the negative of these terms or other similar expressions. Important assumptions include our ability to originate new investments, achieve certain margins and levels of profitability, the availability of additional capital, and the ability to maintain certain debt to asset ratios. In light of these and other uncertainties, the inclusion of a projection or forward-looking statement in this prospectus should not be regarded as a representation by us that our plans or objectives will be achieved. The forward-looking statements contained in this prospectus supplement and the accompanying prospectus include statements as to:

For a discussion of factors that could cause our actual results to differ from forward-looking statements contained in this prospectus supplement and the accompanying prospectus, please see the discussion under “Risk Factors” in the accompanying prospectus.

You should not place undue reliance on these forward-looking statements. The forward-looking statements made in this prospectus relate only to events as of the date on which the statements are made and are excluded from the safe harbor protection provided by Section 27A of the Securities Act of 1933, or the Securities Act. We undertake no obligation to update any forward-looking statement to reflect events or circumstances occurring after the date of this prospectus supplement.

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INDUSTRY AND MARKET DATA

We have compiled certain industry estimates presented in this prospectus supplement and the accompanying prospectus from internally generated information and data. While we believe our estimates are reliable, they have not been verified by any independent sources. The estimates are based on a number of assumptions, including increasing investment in venture capital and private equity-backed companies. Actual results may differ from projections and estimates, and this market may not grow at the rates projected, or at all. If this market fails to grow at projected rates, our business and the market price of our securities, including our common stock, could be materially adversely affected.

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USE OF PROCEEDS

We estimate that the net proceeds we will receive from the sale of the 6,000,000 shares of our common stock in this offering will be approximately $70.4 million (or approximately $81.0 million if the underwriters fully exercise their overallotment option), after deducting the underwriting discount of approximately $2.2 million (or approximately $2.6 million if the underwriters fully exercise their overallotment option) payable by us and estimated offering expenses of approximately $300,000 payable by us.

We expect to use the net proceeds from this offering (i) to fund investments in debt and equity securities in accordance with our investment objective, (ii) to make acquisitions, and (iii) for other general corporate purposes.

We intend to seek to invest the net proceeds received in this offering as promptly as practicable after receipt thereof consistent with our investment objective. We anticipate that substantially all of the net proceeds from any offering of our securities will be used as described above within three to six months, depending on market conditions. We anticipate that the remainder will be used for working capital and general corporate purposes, including potential payments or distributions to shareholders. Pending such use, we will invest a portion of the net proceeds of this offering in short-term investments, such as cash and cash equivalents, which we expect will earn yields substantially lower than the interest income that we anticipate receiving in respect of investments in accordance with our investment objective.

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CAPITALIZATION

The following table sets forth (i) our actual capitalization as of March 31, 2018, and (ii) our capitalization as adjusted to give effect to the sale of 6,000,000 million shares of our common stock in this offering (assuming no exercise of the overallotment option) at a price of $12.15 per share, after deducting the underwriting discounts and commissions of approximately $2.2 million payable by us and estimated offering expenses of approximately $300,000 payable by us. You should read this table together with the “Use of Proceeds” section and our statement of assets and liabilities included elsewhere in this prospectus supplement.

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PRICE RANGE OF COMMON STOCK

Our common stock is traded on the NYSE under the symbol “HTGC.”

The following table sets forth the range of high and low sales prices of our common stock, the sales price as a percentage of NAV and the distributions declared by us for each fiscal quarter. The stock quotations are interdealer quotations and do not include markups, markdowns or commissions.

The last reported price for our common stock on June 7, 2018 was $12.34 per share.

Shares of business development companies may trade at a market price that is less than the value of the net assets attributable to those shares. The possibility that our shares of common stock will trade at a discount from NAV or at premiums that are unsustainable over the long term are separate and distinct from the risk that our NAV will decrease. At times, our shares of common stock have traded at a premium to NAV and at times our shares of common stock have traded at a discount to the net assets attributable to those shares. It is not possible to predict whether the shares offered hereby will trade at, above, or below NAV.

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UNDERWRITING

Under the terms and subject to the conditions contained in an underwriting agreement dated June 12, 2018, we have agreed to sell to the underwriters named below, for whom Wells Fargo Securities, LLC is acting as representative, the following respective numbers of shares of common stock at the offering price less the underwriting discounts and commissions set forth on the cover page of this prospectus supplement:

The underwriting agreement provides that the underwriters are obligated to purchase all of the shares of common stock in the offering if any are purchased, other than those shares covered by the over-allotment option described below, subject to certain conditions precedent. The underwriting agreement also provides that if an underwriter defaults the purchase commitments of non-defaulting underwriters may be increased or the offering may be terminated.

The underwriters propose to offer the shares of common stock offered hereby from time to time for sale in one or more transactions on the NYSE, in the over-the-counter-market, through negotiated transactions or otherwise at market prices prevailing at the time of sale, at prices related to prevailing market prices or at negotiated prices, subject to receipt and acceptance by the underwriters and subject to the underwriters’ right to reject any order in whole or in part. The underwriters may effect such transactions by selling the shares of common stock to or through dealers and such dealers may receive compensation in the form of discounts, concessions or commissions from the underwriter and/or purchasers of shares of common stock for whom they may act as agents or to whom they may sell as principal. The difference between the price at which the underwriters purchase shares and the price at which the underwriters resell such shares, which may include a commission equivalent of up to $0.222 per share, may be deemed underwriting compensation.

We have granted to the underwriter a 30-day option to purchase on a pro rata basis up to 900,000 additional shares at a price of $11.78 per share. The option may be exercised only to cover any over-allotments of common stock.

The following table summarizes the compensation and estimated expenses that we will pay.

Because the Financial Industry Regulatory Authority, or FINRA, views the common stock offered hereby as interests in a direct participation program, the offering is being made in compliance with the requirements of FINRA Rule 2310. Investor suitability with respect to the common stock should be judged similarly to suitability with respect to other securities that are listed for trading on a national securities exchange.

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We expect that our expenses for this offering will be approximately $300,000 (including up to $10,000 in reimbursement of the underwriters’ counsel fees in connection with the review of the terms of the offering by FINRA), excluding underwriting discounts and commissions in connection with this offering.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act, or contribute to payments that the underwriters may be required to make in that respect.

We have agreed that we will not directly or indirectly sell, offer to sell, enter into any agreement to sell, or otherwise dispose of, any equity or equity related securities of the Company or securities convertible into such securities, without the prior written consent of Wells Fargo Securities, LLC for a period of 30 days after the date of this prospectus supplement, except issuances of common stock pursuant to any employee or director compensation, dividend reinvestment, savings, or benefit plan, or distributions to the Company’s directors upon that individual’s election to receive shares of the Company’s common stock in lieu of a cash retainer.

Our directors and senior executive officers have agreed that during the 30 days after the date of this prospectus supplement, subject to certain exceptions, they will not, without the prior written consent of Wells Fargo Securities, LLC offer to sell, contract to sell, or otherwise sell, dispose of, loan, pledge or grant any rights with respect to (collectively, a “Disposition”), any shares of our common stock, any options or warrants to purchase any shares of our common stock or any securities convertible into or redeemable or exchangeable for shares of our common stock now owned or hereafter acquired directly by such person or with respect to which such person has or hereafter acquires the power of disposition. The foregoing restriction has been expressly agreed to preclude the holder of such securities from engaging in any hedging or other transaction which is designed to or reasonably expected to lead to or result in a Disposition of securities during the “lock-up” period, even if such securities would be disposed of by someone other than the holder. Such prohibited hedging or other transactions would include, without limitation, any short sale (whether or not against the box) or any purchase, sale or grant of any right (including, without limitation, any put or call option) with respect to any securities. These lock-up agreements will cover approximately 2,500,000 shares of our outstanding common stock and shares underlying warrants in the aggregate. These agreements will not cover shares acquired in connection with the participation in the Company’s dividend reinvestment plan, shares acquired upon the exercise of stock options pursuant to the Company’s stock option plan, pledges of securities in connection with their purchase upon the exercise of employee stock options following termination of employment with the Company, the sale of shares in connection with net issuances of shares to satisfy tax withholding obligations related to the vesting of shares of restricted stock or the exercise of stock options to purchase shares of the Company’s common stock that were granted pursuant to the Company’s equity compensation plans, or the exercise or conversion of any security into shares of our common stock so long as the shares received remain subject to the “lock-up.” The agreements also exclude dispositions (i) as a bona fide gift or gifts, (ii) as a distribution to partners or shareholders of such person (or in the case of a trust, to the beneficiaries thereof), (iii) to any corporation controlled by the transferor, (iv) to any trust for the direct or indirect benefit of the transferor or their immediate family, provided that such transfer does not involve a disposition for value other than for the benefit of the transferor’s immediate family, and (v) charitable dispositions of securities that do not involve a disposition for value, provided that in each case (i)-(v) the recipient agrees in writing to be bound by the restrictions of the “lock-up.” Wells Fargo Securities, LLC may, in its sole discretion, allow any of these parties to dispose of common stock or other securities prior to the expiration of the 30 day period. There are, however, no agreements between Wells Fargo Securities, LLC and the parties that would allow them to do so as of the date of this prospectus supplement.

Our common stock is listed on the New York Stock Exchange under the symbol “HTGC.”

Until the distribution of the common stock is completed, rules of the Securities and Exchange Commission may limit the ability of the underwriters and certain selling group members to bid for and purchase the common stock. As an exception to these rules, the underwriters are permitted to engage in certain transactions that stabilize, maintain or otherwise affect the price of the common stock.

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In connection with this offering, the underwriters may engage in stabilizing transactions, over-allotment transactions, syndicate covering transactions, penalty and market making bids in accordance with Regulation M under the Securities Act of 1934.

These stabilizing transactions, syndicate covering transactions and penalty bids may have the effect of raising or maintaining the market price of our common stock or preventing or retarding a decline in the market price of the common stock. As a result the price of our common stock may be higher than the price that might otherwise exist in the open market. These transactions may be effected on the NYSE or otherwise and, if commenced may be discontinued at any time.

The underwriters and their respective affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or instruments and may at any time hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

The underwriters will deliver an accompanying prospectus and prospectus supplement to all purchasers of shares of common stock in the short sales. The purchases of shares of common stock in short sales are entitled to the same remedies under the federal securities laws as any other purchaser of shares of common stock covered by this prospectus supplement.

The underwriters are not obligated to engage in any of the transactions described above. If it does engage in any of these transactions, it may discontinue them at any time.

Other Relationships

The underwriters and their affiliates have provided in the past and may provide from time to time in the future in the ordinary course of their business certain commercial banking, financial advisory, investment

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banking and other services to Hercules or our portfolio companies for which they have received or will be entitled to receive separate fees. In particular, the underwriters or their affiliates may execute transactions with Hercules or on behalf of Hercules or any of our portfolio companies.

The underwriters or their affiliates may also trade in our securities, securities of our portfolio companies or other financial instruments related thereto for their own accounts or for the account of others and may extend loans or financing directly or through derivative transactions to us or any of our portfolio companies.

We may purchase securities of third parties from the underwriters or their affiliates after the offering. However, we have not entered into any agreement or arrangement regarding the acquisition of any such securities, and we may not purchase any such securities. We would only purchase any such securities if—among other things—we identified securities that satisfied our investment needs and completed our due diligence review of such securities.

After the date of this prospectus supplement, the underwriters and their affiliates may from time to time obtain information regarding specific portfolio companies or us that may not be available to the general public. Any such information is obtained by the underwriters and their affiliates in the ordinary course of its business and not in connection with the offering of the shares. In addition, after the offering period for the sale of the shares, the underwriters or their affiliates may develop analyses or opinions related to Hercules or our portfolio companies and buy or sell interests in one or more of our portfolio companies on behalf of their proprietary or client accounts and may engage in competitive activities. There is no obligation on behalf of these parties to disclose their respective analyses, opinions or purchase and sale activities regarding any portfolio company or regarding us to our noteholders or any other persons.

In the ordinary course of their various business activities, the underwriters and their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. Certain of the underwriters and their affiliates that have a lending relationship with us routinely hedge their credit exposure to us consistent with their customary risk management policies. Typically, such underwriters and their affiliates would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the shares offered hereby. Any such short positions could adversely affect future trading prices of the shares offered hereby. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

The principal business address of Wells Fargo Securities, LLC is 550 South Tryon Street, Charlotte, North Carolina 28202.

Notice to Prospective Investors in Australia

No placement document, prospectus, product disclosure statement or other disclosure document has been lodged with the Australian Securities and Investments Commission, or ASIC, in relation to the offering. This prospectus supplement and accompanying prospectus do not constitute a prospectus, product disclosure statement or other disclosure document under the Corporations Act 2001, or Corporations Act, and do not purport to include the information required for a prospectus, product disclosure statement or other disclosure document under the Corporations Act.

Any offer in Australia of the common stock may only be made to persons known as the Exempt Investors who are “sophisticated investors” (within the meaning of section 708(8) of the Corporations Act), “professional investors” (within the meaning of section 708(11) of the Corporations Act) or otherwise pursuant to one or more

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exemptions contained in section 708 of the Corporations Act so that it is lawful to offer the common stock without disclosure to investors under Chapter 6D of the Corporations Act.

The common stock applied for by Exempt Investors in Australia must not be offered for sale in Australia in the period of 12 months after the date of allotment under the offering, except in circumstances where disclosure to investors under Chapter 6D of the Corporations Act would not be required pursuant to an exemption under section 708 of the Corporations Act or otherwise or where the offer is pursuant to a disclosure document which complies with Chapter 6D of the Corporations Act. Any person acquiring common stock must observe such Australian on-sale restrictions.

This prospectus supplement and accompanying prospectus contain general information only and do not take account of the investment objectives, financial situation or particular needs of any particular person. They do not contain any securities recommendations or financial product advice. Before making an investment decision, investors need to consider whether the information in this prospectus supplement and accompanying prospectus is appropriate to their needs, objectives and circumstances, and, if necessary, seek expert advice on those matters.

Notice to Prospective Investors in the Dubai International Financial Centre

This prospectus supplement and accompanying prospectus relate to an Exempt Offer in accordance with the Offered Securities Rules of the Dubai Financial Services Authority, or DFSA. This prospectus supplement and accompanying prospectus are intended for distribution only to persons of a type specified in the Offered Securities Rules of the DFSA. It must not be delivered to, or relied on by, any other person. The DFSA has no responsibility for reviewing or verifying any documents in connection with Exempt Offers. The DFSA has not approved this prospectus supplement and accompanying prospectus nor taken steps to verify the information set forth herein and has no responsibility for the prospectus supplement and accompanying prospectus. The common stock to which this prospectus supplement and accompanying prospectus relate may be illiquid or subject to restrictions on their resale. Prospective purchasers of the common stock offered should conduct their own due diligence on the common stock. If you do not understand the contents of this prospectus supplement and accompanying prospectus you should consult an authorized financial advisor.

Notice to Prospective Investors in Hong Kong

The common stock has not been offered or sold and will not be offered or sold in Hong Kong, by means of any document, other than (a) to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571) of Hong Kong and any rules made under that Ordinance; or (b) in other circumstances which do not result in the document being a “prospectus” as defined in the Companies Ordinance (Cap. 32) of Hong Kong or which do not constitute an offer to the public within the meaning of that Ordinance. No advertisement, invitation or document relating to the common stock has been or may be issued or has been or may be in the possession of any person for the purposes of issue, whether in Hong Kong or elsewhere, which is directed at, or the contents of which are likely to be accessed or read by, the public of Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to common stock which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” as defined in the Securities and Futures Ordinance and any rules made under that Ordinance.

Notice to Prospective Investors in Singapore

This prospectus has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the shares may not be circulated or distributed, nor may the shares be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor (as defined under Section 4A of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”)) under Section 274 of the SFA, (ii) to a

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relevant person (as defined in Section 275(2) of the SFA) pursuant to Section 275(1) of the SFA, or any person pursuant to Section 275(1A) of the SFA, and in accordance with the conditions specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA, in each case subject to conditions set forth in the SFA.

Where the shares are subscribed or purchased under Section 275 of the SFA by a relevant person which is a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor, the securities (as defined in Section 239(1) of the SFA) of that corporation shall not be transferable for 6 months after that corporation has acquired the shares under Section 275 of the SFA except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person (as defined in Section 275(2) of the SFA), (2) where such transfer arises from an offer in that corporation’s securities pursuant to Section 275(1A) of the SFA, (3) where no consideration is or will be given for the transfer, (4) where the transfer is by operation of law, (5) as specified in Section 276(7) of the SFA, or (6) as specified in Regulation 32 of the Securities and Futures (Offers of Investments) (Shares and Debentures) Regulations 2005 of Singapore (“Regulation 32”).

Where the shares are subscribed or purchased under Section 275 of the SFA by a relevant person which is a trust (where the trustee is not an accredited investor (as defined in Section 4A of the SFA)) whose sole purpose is to hold investments and each beneficiary of the trust is an accredited investor, the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferable for 6 months after that trust has acquired the shares under Section 275 of the SFA except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person (as defined in Section 275(2) of the SFA), (2) where such transfer arises from an offer that is made on terms that such rights or interest are acquired at a consideration of not less than $200,000 (or its equivalent in a foreign currency) for each transaction (whether such amount is to be paid for in cash or by exchange of securities or other assets), (3) where no consideration is or will be given for the transfer, (4) where the transfer is by operation of law, (5) as specified in Section 276(7) of the SFA, or (6) as specified in Regulation 32.

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MANAGEMENT

Solely as a result of their ownership of common stock in one of the underwriters in this offering, two of our independent directors, Doreen Woo Ho and Robert P. Badavas, will each be considered an “interested person” of Hercules Capital, Inc. as defined in the 1940 Act until the completion of this offering.

LEGAL MATTERS

Certain legal matters in connection with the securities offered hereby will be passed upon for us by Dechert LLP, New York, NY. Certain legal matters in connection with the securities offered hereby will be passed upon for the underwriters by Fried, Frank, Harris, Shriver & Jacobson LLP, New York, NY.

EXPERTS

The consolidated financial statements as of December 31, 2017 and 2016 and for each of the three years in the period ended December 31, 2017 and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Annual Report on Internal Control over Financial Reporting) as of December 31, 2017 included in the accompanying prospectus have been so included in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

AVAILABLE INFORMATION

We have filed with the SEC a registration statement on Form N-2, together with all amendments and related exhibits, under the Securities Act, with respect to our securities offered by this prospectus supplement and the accompanying prospectus. The registration statement contains additional information about us and our securities being offered by this prospectus supplement and the accompanying prospectus.

We file annual, quarterly and current periodic reports, proxy statements and other information with the SEC under the Exchange Act. You may inspect and copy these reports, proxy statements and other information, as well as the registration statement of which this prospectus supplement and accompanying prospectus form a part and the related exhibits and schedules, at the Public Reference Room of the SEC at 100 F Street, N.E., Washington, D.C. 20549-0102. You may obtain information on the operation of the Public Reference Room by calling the SEC at 202-551-8090. The SEC maintains an Internet website that contains reports, proxy and information statements and other information filed electronically by us with the SEC which are available on the SEC’s Internet website at http://www.sec.gov. Copies of these reports, proxy and information statements and other information may be obtained, after paying a duplicating fee, by electronic request at the following E-mail address: publicinfo@sec.gov, or by writing the SEC’s Public Reference Section, Washington, D.C. 20549-0102.

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$750,000,000

Common Stock

Preferred Stock

Warrants

Subscription Rights

Debt Securities

This prospectus relates to the offer, from time to time, in one or more offerings or series, up to $750,000,000 of shares of our common stock, par value $0.001 per share, preferred stock, par value $0.001 per share, warrants representing rights to purchase shares of our common stock, preferred stock or debt securities, subscription rights or debt securities, which we refer to, collectively, as the “securities.” The preferred stock, debt securities, subscription rights and warrants offered hereby may be convertible or exchangeable into shares of our common stock. We may sell our securities through underwriters or dealers, “at-the-market” to or through a market maker into an existing trading market or otherwise directly to one or more purchasers, including existing stockholders in a rights offering, or through agents or through a combination of methods of sale, including auctions. The identities of such underwriters, dealers, market makers or agents, as the case may be, will be described in one or more supplements to this prospectus. The securities may be offered at prices and on terms to be described in one or more supplements to this prospectus.

In the event we offer common stock, the offering price per share will not be less than the net asset value per share of our common stock at the time we make the offering except (1) in connection with a rights offering to our existing stockholders, (2) with the consent of the holders of the majority of our voting securities and approval of our Board of Directors, or (3) under such circumstances as the Securities and Exchange Commission may permit. See “Risk Factors” for more information.

We are a specialty finance company focused on providing senior secured loans to high-growth, innovative venture capital-backed companies in a variety of technology, life sciences and sustainable and renewable technology industries. We primarily finance privately-held companies backed by leading venture capital and private equity firms and publicly-traded companies that lack access to public capital or are sensitive to equity ownership dilution. We source our investments through our principal office located in Palo Alto, CA, as well as through additional offices in Boston, MA, New York, NY, Washington, DC, Hartford, CT and San Diego, CA. Our goal is to be the leading structured debt financing provider for venture capital-backed companies in technology-related industries requiring sophisticated and customized financing solutions. We invest primarily in structured debt with warrants and, to a lesser extent, in senior debt and equity investments. We use the term “structured debt with warrants” to refer to any debt investment, such as a senior or subordinated secured loan, that is coupled with an equity component, including warrants, options or other rights to purchase common or preferred stock. Our structured debt with warrants investments typically are secured by some or all of the assets of the portfolio company. We invest primarily in private companies but also have investments in public companies.

Our investment objective is to maximize our portfolio total return by generating current income from our debt investments and capital appreciation from our warrant and equity-related investments. We are an internally-managed, non-diversified closed-end investment company that has elected to be regulated as a business development company under the Investment Company Act of 1940, as amended.

Our common stock is traded on the New York Stock Exchange, or NYSE, under the symbol “HTGC.” On May 29, 2018, the last reported sale price of a share of our common stock on the NYSE, was $12.40. The net asset value per share of our common stock at March 31, 2018 (the last date prior to the date of this prospectus on which we determined net asset value) was $9.72.

An investment in our securities may be speculative and involves risks including a heightened risk of total loss of investment. In addition, the companies in which we invest are subject to special risks. See “Risk Factors” beginning on page 14 to read about risks that you should consider before investing in our securities, including the risk of leverage.

Please read this prospectus before investing and keep it for future reference. It contains important information about us that a prospective investor ought to know before investing in our securities. We file annual, quarterly and current reports, proxy statements and other information about us with the Securities and Exchange Commission. The information is available free of charge by contacting us at 400 Hamilton Avenue, Suite 310, Palo Alto, California 94301 or by telephone calling collect at (650) 289-3060 or on our website at www.htgc.com. The SEC also maintains a website at www.sec.gov that contains such information.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus may not be used to consummate sales of any securities unless accompanied by a prospectus supplement.

The date of this prospectus is June 5, 2018

You should rely only on the information contained in this prospectus. We have not authorized any dealer, salesperson or other person to provide you with different information or to make representations as to matters not stated in this prospectus. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus is not an offer to sell, or a solicitation of an offer to buy, any securities by any person in any jurisdiction where it is unlawful for that person to make such an offer or solicitation or to any person in any jurisdiction to whom it is unlawful to make such an offer or solicitation. The information in this prospectus is accurate only as of its date, and under no circumstances should the delivery of this prospectus or the sale of any securities imply that the information in this prospectus is accurate as of any later date or that the affairs of Hercules Capital, Inc. have not changed since the date hereof. This prospectus will be updated to reflect material changes.

TABLE OF CONTENTS

Hercules Capital, Inc., our logo and other trademarks of Hercules Capital, Inc. mentioned in this prospectus are the property of Hercules Capital, Inc. All other trademarks or trade names referred to in this prospectus are the property of their respective owners.

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we have filed with the Securities and Exchange Commission using the “shelf” registration process. Under the shelf registration process, which constitutes a delayed offering in reliance on Rule 415 under the Securities Act of 1933, as amended (the “Securities Act”), we may offer, from time to time, up to $750,000,000 of our common stock, preferred stock, warrants representing rights to purchase shares of our common stock, preferred stock or debt securities, subscription rights or debt securities on the terms to be determined at the time of the offering. We may sell our securities through underwriters or dealers, “at-the-market” to or through a market maker, into an existing trading market or otherwise directly to one or more purchasers, including existing stockholders in a rights offering, or through agents or through a combination of methods of sale. The identities of such underwriters, dealers, market makers or agents, as the case may be, will be described in one or more supplements to this prospectus. The securities may be offered at prices and on terms described in one or more supplements to this prospectus. This prospectus provides you with a general description of the securities that we may offer. Each time we use this prospectus to offer securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. Please carefully read this prospectus and any such supplements together with the additional information described under “Available Information” in the “Summary” and “Risk Factors” sections before you make an investment decision.

A prospectus supplement may also add to, update or change information contained in this prospectus.

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FEES AND EXPENSES

The following table is intended to assist you in understanding the various costs and expenses that an investor in our common stock will bear directly or indirectly. However, we caution you that some of the percentages indicated in the table below are estimates and may vary. The footnotes to the fee table state which items are estimates. Except where the context suggests otherwise, whenever this prospectus contains a reference to fees or expenses paid by “you” or “us” or that “we” will pay fees or expenses, stockholders will indirectly bear such fees or expenses as investors in Hercules Capital, Inc.

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Example

The following example demonstrates the projected dollar amount of total cumulative expenses that would be incurred over various periods with respect to a hypothetical investment in our common stock. These amounts are based upon our payment of annual operating expenses at the levels set forth in the table above and assume no additional leverage.

The example and the expenses in the tables above should not be considered a representation of our future expenses, and actual expenses may be greater or lesser than those shown. Moreover, while the example assumes, as required by the applicable rules of the SEC, a 5% annual return, our performance will vary and may result in a return greater or lesser than 5%. In addition, while the example assumes reinvestment of all distributions at net asset value (“NAV”), participants in our dividend reinvestment plan may receive shares valued at the market price in effect at that time. This price may be at, above or below NAV. See “Dividend Reinvestment Plan” for additional information regarding our dividend reinvestment plan.

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SELECTED CONSOLIDATED FINANCIAL DATA

The selected consolidated financial data should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” “Senior Securities” and the consolidated financial statements and related notes included elsewhere herein. The selected balance sheet data as of the end of fiscal year 2017, 2016, 2015, 2014, and 2013 and the financial statement of operations data for fiscal years 2017, 2016, 2015, 2014, and 2013 has been derived from our audited financial statements, which have been audited by PricewaterhouseCoopers LLP, our independent registered public accounting firm, but not all of which are presented in this Form N-2.” The historical data are not necessarily indicative of results to be expected for any future period. The selected financial and other data for the three-months ended March 31, 2018 and other quarterly financial information is derived from our unaudited financial statements, but in the opinion of management, reflects all adjustments (consisting only of normal recurring adjustments) that are necessary to present fairly the results of such interim periods. Interim results as of and for the three-months ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018.

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The following tables set forth certain quarterly financial information for each of the eight quarters up to and ending December 31, 2017 and the quarter ending March 31, 2018. This information was derived from the Company’s unaudited consolidated financial statements. Results for any quarter are not necessarily indicative of results for the full year or for any future quarter.

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RISK FACTORS

Investing in our securities may be speculative and involves a high degree of risk. You should consider carefully the risks described below and all other information contained in this prospectus, including our financial statements and the related notes and the schedules and exhibits to this prospectus. The risks set forth below are not the only risks we face. Additional risks and uncertainties not presently known to us or not presently deemed material by us may also impair our operations and performance. If any of the following risks occur, our business, financial condition and results of operations could be materially adversely affected. In such case, our NAV and the trading price of our securities could decline, and you may lose all or part of your investment.

Risks Related to our Business Structure

As an internally managed business development company, we are subject to certain restrictions that may adversely affect our business.

As an internally managed business development company, the size and categories of our assets under management is limited, and we are unable to offer as wide a variety of financial products to prospective portfolio companies and sponsors (potentially limiting the size and diversification of our asset base). We therefore may not achieve efficiencies of scale and greater management resources available to externally managed business development companies.

Additionally, as an internally managed business development company, our ability to offer more competitive and flexible compensation structures, such as offering both a profit sharing plan and an equity incentive plan, is subject to the limitations imposed by the 1940 Act, which limits our ability to attract and retain talented investment management professionals. As such, these limitations could inhibit our ability to grow, pursue our business plan and attract and retain professional talent, any or all of which may have a negative impact on our business, financial condition and results of operations.

As an internally managed business development company, we are dependent upon key management personnel for their time availability and for our future success, particularly Manuel A. Henriquez, and if we are not able to hire and retain qualified personnel, or if we lose any member of our senior management team, our ability to implement our business strategy could be significantly harmed.

As an internally managed business development company, our ability to achieve our investment objectives and to make distributions to our stockholders depends upon the performance of our senior management. We depend upon the members of our senior management, particularly Mr. Henriquez, as well as other key personnel for the identification, final selection, structuring, closing and monitoring of our investments. These employees have critical industry experience and relationships on which we rely to implement our business plan. If we lose the services of Mr. Henriquez or any senior management members, we may not be able to operate the business as we expect, and our ability to compete could be harmed, which could cause our operating results to suffer. Furthermore, we do not have an employment agreement with Mr. Henriquez or our senior management that restricts them from creating new investment vehicles subject to compliance with applicable law. We believe our future success will depend, in part, on our ability to identify, attract and retain sufficient numbers of highly skilled employees. If we do not succeed in identifying, attracting and retaining such personnel, we may not be able to operate our business as we expect. In connection with our recruiting, branding and marketing efforts, we may, among other things, make charitable contributions in amounts we believe to be immaterial. We believe that many of these contributions help us raise our profile in the communities and benefit us in attracting and retaining talent and investment opportunities.

As an internally managed business development company, our compensation structure is determined and set by our Board of Directors. This structure currently includes salary and bonus and incentive compensation, which is issued through grants and subsequent vesting of restricted stock. We are not generally permitted by the 1940 Act to employ an incentive compensation structure that directly ties performance of our investment portfolio and results of operations to compensation owing to our granting of restricted stock as incentive compensation.

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Members of our senior management may receive offers of more flexible and attractive compensation arrangements from other companies, particularly from investment advisers to externally managed business development companies that are not subject to the same limitations on incentive-based compensation that we, as an internally managed business development company are subject to. We do not currently have agreements with certain members of our senior management that prohibit them from leaving and competing with our business and certain States limit our ability to have such agreements. A departure by one or more members of our senior management could have a negative impact on our business, financial condition and results of operations.

Our business model depends to a significant extent upon strong referral relationships with venture capital and private equity fund sponsors, and our inability to develop or maintain these relationships, or the failure of these relationships to generate investment opportunities, could adversely affect our business.

We expect that members of our management team will maintain their relationships with venture capital and private equity firms, and we will rely to a significant extent upon these relationships to provide us with our deal flow. If we fail to maintain our existing relationships, our relationships become strained as a result of enforcing our rights with respect to non-performing portfolio companies in protecting our investments or we fail to develop new relationships with other firms or sources of investment opportunities, then we will not be able to grow our investment portfolio. In addition, persons with whom members of our management team have relationships are not obligated to provide us with investment opportunities and, therefore, there is no assurance that such relationships will lead to the origination of debt or other investments.

We may be the target of litigation.

We may be the target of securities litigation in the future, particularly if the trading price of our common stock and our debt securities fluctuates significantly. We could also generally be subject to litigation, including derivative actions by our stockholders. Any litigation could result in substantial costs and divert management’s attention and resources from our business and cause a material adverse effect on our business, financial condition and results of operations.

We operate in a highly competitive market for investment opportunities, and we may not be able to compete effectively.

A number of entities compete with us to make the types of investments that we plan to make in prospective portfolio companies. We compete with a large number of venture capital and private equity firms, as well as with other investment funds, business development companies, investment banks and other sources of financing, including traditional financial services companies such as commercial banks and finance companies. Many of our competitors are substantially larger and have considerably greater financial, technical, marketing and other resources than we do. For example, some competitors may have a lower cost of funds and/or access to funding sources that are not available to us. This may enable some competitors to make loans with interest rates that are comparable to or lower than the rates that we typically offer.

A significant increase in the number and/or the size of our competitors, including traditional commercial lenders and other financing sources, in technology-related industries could force us to accept less attractive investment terms. We may be unable to capitalize on certain opportunities if we do not match competitors’ pricing, terms and structure. If we do match competitors’ pricing, terms or structure, we may experience decreased net interest income and increased risk of credit losses. In addition, some of our competitors may have higher risk tolerances or different risk assessments, which could allow them to consider a wider variety of investments, establish more relationships and build their market shares. An increasing number of competitors may also have the effect of compressing our margins, which could harm our ability to retain employees, increase our operating costs, and decrease the amount and frequency of future distributions. Furthermore, many potential competitors are not subject to the regulatory restrictions that the 1940 Act imposes on us as a business

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development company or that the Code imposes on us as a RIC. If we are not able to compete effectively, our business, financial condition, and results of operations will be adversely affected. As a result of this competition, there can be no assurance that we will be able to identify and take advantage of attractive investment opportunities, or that we will be able to fully invest our available capital.

If we are unable to manage our future growth effectively, we may be unable to achieve our investment objective, which could adversely affect our financial condition and results of operations and cause the value of your investment to decline.

Our ability to achieve our investment objective will depend on our ability to sustain growth. Sustaining growth will depend, in turn, on our senior management team’s ability to identify, evaluate, finance and invest in suitable companies that meet our investment criteria. Accomplishing this result on a cost-effective basis is largely a function of our marketing capabilities, our management of the investment process, our ability to provide efficient services and our access to financing sources on acceptable terms. Organizational growth and scale-up of our investments could strain our existing managerial, investment, financial and other resources. Management of our growth could divert financial resources from other projects. Failure to manage our future growth effectively could lead to a decrease in our future distributions and have a material adverse effect on our business, financial condition and results of operations.

Because we intend to distribute substantially all of our income to our stockholders in order to qualify as a RIC, we will continue to need additional capital to finance our growth. If additional funds are unavailable or not available on favorable terms, our ability to grow will be impaired.

In order to satisfy the tax requirements applicable to a RIC and to minimize or avoid being subject to income and excise taxes, we intend to make distributions to our stockholders treated as dividends for U.S. federal income tax purposes generally of an amount at least equal to substantially all of our net ordinary income and realized net capital gains except for certain realized net capital gains, which we may retain, pay applicable income taxes with respect thereto and elect to treat as deemed distributions to our stockholders. As a business development company, we generally are required to meet a coverage ratio of total assets to total borrowings and other senior securities, which includes all of our borrowings and any preferred stock that we may issue in the future, of at least 200% (or 150%, subject to certain approval and disclosure requirements). This requirement limits the amount that we may borrow. This limitation may prevent us from incurring debt and require us to raise additional equity at a time when it may be disadvantageous to do so. We cannot assure you that debt and equity financing will be available to us on favorable terms, or at all, and debt financings may be restricted by the terms of any of our outstanding borrowings. If we are unable to incur additional debt, we may be required to raise additional equity at a time when it may be disadvantageous to do so. In addition, shares of closed-end investment companies have recently traded at discounts to their NAV.

This characteristic of closed-end investment companies is separate and distinct from the risk that our NAV per share may decline. We cannot predict whether shares of our common stock will trade above, at or below our NAV. If our common stock trades below its NAV, we generally will not be able to issue additional shares of our common stock at its market price without first obtaining the approval for such issuance from our stockholders and our independent directors. If additional funds are not available to us, we could be forced to curtail or cease new lending and investment activities, and our NAV could decline. In addition, our results of operations and financial condition could be adversely affected.

Because most of our investments typically are not in publicly-traded securities, there is uncertainty regarding the value of our investments, which could adversely affect the determination of our NAV.

At March 31, 2018, portfolio investments, whose fair value is determined in good faith by the Board of Directors, were approximately 91.6% of our total assets. We expect our investments to continue to consist

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primarily of securities issued by privately-held companies, the fair value of which is not readily determinable. In addition, we are not permitted to maintain a general reserve for anticipated loan losses. Instead, we are required by the 1940 Act to specifically value each investment and record an unrealized gain or loss for any asset that we believe has increased or decreased in value.

There is no single standard for determining fair value in good faith. We value these securities at fair value as determined in good faith by our Board of Directors, based on the recommendations of our Audit Committee. In making a good faith determination of the value of these securities, we generally start with the cost basis of each security, which includes the amortized original issue discount, or OID, and payment-in-kind, or PIK, interest, if any. The Audit Committee uses its best judgment in arriving at the fair value of these securities. As a result, determining fair value requires that judgment be applied to the specific facts and circumstances of each portfolio investment while applying a valuation process for the types of investments we make, which includes but is not limited to deriving a hypothetical exit price.

However, the Board of Directors retains ultimate authority as to the appropriate valuation of each investment. Because such valuations are inherently uncertain and may be based on estimates, our determinations of fair value may differ materially from the values that would be assessed if a ready market for these securities existed. We adjust quarterly the valuation of our portfolio to reflect the Board of Directors’ determination of the fair value of each investment in our portfolio. Any changes in fair value are recorded in our statement of operations as net change in unrealized appreciation or depreciation. Our NAV could be adversely affected if our determinations regarding the fair value of our investments were materially higher than the values that we ultimately realize upon the disposal of such securities.

Because we have substantial indebtedness, there could be increased risk in investing in our company.

Lenders have fixed dollar claims on our assets that are superior to the claims of stockholders, and we have granted, and may in the future grant, lenders a security interest in our assets in connection with borrowings. In the case of a liquidation event, those lenders would receive proceeds before our stockholders. In addition, borrowings, also known as leverage, magnify the potential for gain or loss on amounts invested and, therefore, increase the risks associated with investing in our securities. Leverage is generally considered a speculative investment technique. If the value of our assets increases, then leverage would cause the NAV attributable to our common stock to increase more than it otherwise would have had we not leveraged. Conversely, if the value of our assets decreases, leverage would cause the NAV attributable to our common stock to decline more than it otherwise would have had we not used leverage. Similarly, any increase in our revenue in excess of interest expense on our borrowed funds would cause our net income to increase more than it would without the leverage. Any decrease in our revenue would cause our net income to decline more than it would have had we not borrowed funds and could negatively affect our ability to make distributions on common stock. Our ability to service any debt that we incur will depend largely on our financial performance and will be subject to prevailing economic conditions and competitive pressures. We and, indirectly, our stockholders will bear the cost associated with our leverage activity. If we are not able to service our substantial indebtedness, our business could be harmed materially.

Our Credit Facilities, our 2022 Notes, our 2024 Notes, our 2025 Notes, our 2021 Asset-Backed Notes, and our 2022 Convertible Notes (as each term is defined herein) contain financial and operating covenants that could restrict our business activities, including our ability to declare dividend distributions if we default under certain provisions.

As of March 31, 2018, we had no borrowings outstanding under the $120.0 million revolving senior secured credit facility with Wells Fargo Capital Finance, LLC (the “Wells Facility”) and the $75.0 million revolving senior secured credit facility with MUFG Union Bank, N.A. (the “Union Bank Facility,” and together with the Wells Facility, the “Credit Facilities”). In addition, as of March 31, 2018, we had approximately $190.2 million of indebtedness outstanding incurred by our SBIC subsidiaries, approximately $150.0 million in aggregate principal amount of 4.625% notes due 2022 (the “2022 Notes”), approximately $183.5 million in aggregate

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principal amount of 2024 Notes, approximately $33.6 million in aggregate principal amount of fixed rate asset-backed notes (the “2021 Asset-Backed Notes”) in connection with our $237.4 million debt securitization (the “2014 Debt Securitization”) and approximately $230.0 million in aggregate principal amount of 4.375% convertible notes due 2022 (the “2022 Convertible Notes”). Additionally, subsequent to March 31, 2018, we had approximately $75.0 million in aggregate principal amount of 2025 Notes.

There can be no assurance that we will be successful in obtaining any additional debt capital on terms acceptable to us or at all. If we are unable to obtain debt capital, then our equity investors will not benefit from the potential for increased returns on equity resulting from leverage to the extent that our investment strategy is successful and we may be limited in our ability to make new commitments or fundings to our portfolio companies.

As a business development company, under the 1940 Act, generally, we are not permitted to incur indebtedness unless immediately after such borrowing we have an asset coverage for total borrowings of at least 200% (i.e., the amount of debt may not exceed 50% of the value of our assets). In addition, we may not be permitted to declare any cash distribution on our outstanding common shares, or purchase any such shares, unless, at the time of such declaration or purchase, we have asset coverage of at least 200% after deducting the amount of such distribution or purchase price. If this ratio declines below 200%, we may not be able to incur additional debt and may need to sell a portion of our investments to repay some debt when it is disadvantageous to do so, and we may not be able to make distributions. The Small Business Credit Availability Act, which was signed into law in March 2018, modifies this section of the 1940 Act and decreases this percentage from 200% to 150% (subject to either stockholder approval or approval of both a majority of the board of directors and a majority of directors who are not interested persons). As a result of this new law, we may be able to incur additional indebtedness subject to relevant approval and disclosure requirements and, therefore, your risk of an investment in us may increase. Rating agencies may also decide to review our credit ratings and those of other business development companies in light of this new law as well as any corresponding changes to asset coverage ratios and consider downgrading such ratings, including a downgrade from an investment grade rating to a non-investment grade rating. Such a downgrade in our credit ratings may adversely affect our securities. See “—A downgrade, suspension or withdrawal of the credit rating assigned by a rating agency to us or our debt securities, if any, or change in the debt markets could cause the liquidity or market value of our debt securities to decline significantly.”

As of March 31, 2018, our asset coverage ratio under our regulatory requirements as a business development company was 238.2% excluding our SBIC debentures as a result of our exemptive order from the SEC that allows us to exclude all SBA leverage from our asset coverage ratio and was 204.8% when including all SBA leverage.

Based on assumed leverage equal to 95.0% of our net assets as of March 31, 2018, our investment portfolio would have been required to experience an annual return of at least 2.6% to cover annual interest payments on our additional indebtedness.

Illustration. The following table illustrates the effect of leverage on returns from an investment in our common stock assuming various annual returns, net of expenses. The calculations in the table below are hypothetical and actual returns may be higher or lower than those appearing below.

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It is likely that the terms of any current or future long-term or revolving credit or warehouse facility we may enter into in the future could constrain our ability to grow our business.

Under our borrowings and our Credit Facilities, current lenders have, and any future lender or lenders may have, fixed dollar claims on our assets that are senior to the claims of our stockholders and, thus, will have a preference over our stockholders with respect to our assets pledged as collateral under the Credit Facilities. Our Credit Facilities and borrowings also subject us to various financial and operating covenants, including, but not limited to, maintaining certain financial ratios and minimum tangible net worth amounts. Future credit facilities and borrowings will likely subject us to similar or additional covenants. In addition, we may grant a security interest in our assets in connection with any such credit facilities and borrowings.

Our Credit Facilities generally contain customary default provisions such as a minimum net worth amount, a profitability test, and a restriction on changing our business and loan quality standards. In addition, our Credit Facilities require or are expected to require the repayment of all outstanding debt on the maturity which may disrupt our business and potentially the business of our portfolio companies that are financed through the facilities. An event of default under these facilities would likely result, among other things, in termination of the availability of further funds under the facilities and accelerated maturity dates for all amounts outstanding under the facilities, which would likely disrupt our business and, potentially, the business of the portfolio companies whose loans we finance through the facilities. This could reduce our revenues and, by delaying any cash payment allowed to us under our facilities until the lender has been paid in full, reduce our liquidity and cash flow and impair our ability to grow our business and our ability to make distributions sufficient to maintain our ability to be subject to tax as a RIC.

The terms of future available financing may place limits on our financial and operation flexibility. If we are unable to obtain sufficient capital in the future, we may be forced to reduce or discontinue our operations, not be able to make new investments, or otherwise respond to changing business conditions or competitive pressures.

In addition to regulatory requirements that restrict our ability to raise capital, our 2022 Notes, 2024 Notes, 2025 Notes, 2022 Convertible Notes, and Credit Facilities contain various covenants which, if not complied with, could require accelerated repayment under the facility or require us to repurchase the 2022 Notes, 2024 Notes, 2025 Notes, or 2022 Convertible Notes thereby materially and adversely affecting our liquidity, financial condition, results of operations and ability to pay distributions.

The credit agreements governing our 2022 Notes, 2024 Notes, 2025 Notes, 2022 Convertible Notes, and Credit Facilities require us to comply with certain financial and operational covenants. These covenants require us to, among other things, maintain certain financial ratios, including asset coverage, debt to equity and interest coverage. Our ability to continue to comply with these covenants in the future depends on many factors, some of which are beyond our control. There are no assurances that we will be able to comply with these covenants. Failure to comply with these covenants would result in a default which, if we were unable to obtain a waiver from the lenders under our Credit Facilities and could accelerate repayment under the facilities or the 2022 Notes, 2024 Notes, 2025 Notes or 2022 Convertible Notes and thereby have a material adverse impact on our liquidity, financial condition, results of operations and ability to pay a sufficient amount of distributions and maintain our ability to be subject to tax as a RIC. We may not have enough available cash or be able to obtain financing at the time we are required to make repurchases. See “Management’s Discussion and Analysis of Financial Condition of Results of Operations—Borrowings”.

Acquisitions or investments that we may pursue could be unsuccessful, consume significant resources and require the incurrence of additional indebtedness.

We regularly consider acquisitions and investments that complement our existing business. These possible acquisitions and investments involve or may involve significant cash expenditures, debt incurrence, operating losses and expenses that could have a material effect on our financial condition and operating results.

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In particular, if we incur additional debt, our liquidity and financial stability could be impaired as a result of using a significant portion of available cash or borrowing capacity to finance an acquisition. Moreover, we may face an increase in interest expense or financial leverage if additional debt is incurred to finance an acquisition, which may, among other things, adversely affect our various financial ratios and our compliance with the conditions of our existing indebtedness. In addition, such additional indebtedness may be secured by liens on our assets.

Acquisitions involve numerous other risks, including:

To the extent we pursue an acquisition that causes us to incur unexpected costs or that fails to generate expected returns, our financial position, results of operations and cash flows may be adversely affected, and our ability to service indebtedness, including our outstanding notes, may be negatively impacted.

In addition, we may fail in our pursuit of an acquisition and, instead, one of our competitors may successfully obtain the target and deprive us of an important opportunity and allow them to grow larger giving them the ability to have a lower cost of capital and competitive advantage in the market (including by being able to offer better pricing and larger loans) and, as a larger company, potentially giving them more valuable equity currency to do other transactions.

We may be unable to obtain debt capital on favorable terms or at all, in which case we would not be able to use leverage to increase the return on our investments.

If we are unable to obtain debt capital, then our equity investors will not benefit from the potential for increased returns on equity resulting from leverage to the extent that our investment strategy is successful and we may be limited in our ability to make new commitments or fundings to our portfolio companies. An inability to obtain debt capital may also limit our ability to refinance existing indebtedness, particularly during periods of adverse credit market conditions when refinancing indebtedness may not be available under interest rates and other terms acceptable to us or at all.

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The Wells Facility and the Union Bank Facility mature in August 2019 and May 2020, respectively, and any inability to renew, extend or replace our Credit Facilities could adversely impact our liquidity and ability to find new investments or maintain distributions to our stockholders.

As of March 31, 2018, we had two available secured credit facilities, the Wells Facility and the Union Bank Facility, which mature in August 2019 and May 2020, respectively. There can be no assurance that we will be able to renew, extend or replace our Credit Facilities upon maturity on terms that are favorable to us, if at all. Our ability to renew, extend or replace the Credit Facility will be constrained by then-current economic conditions affecting the credit markets. In the event that we are not able to renew, extend or replace either Credit Facility at the time of its maturity, this could have a material adverse effect on our liquidity and ability to fund new investments, our ability to make distributions to our stockholders and our ability to qualify as a RIC.

We are subject to certain risks as a result of our interests in connection with the 2014 Debt Securitization and our equity interest in the 2014 Securitization Issuer.

On November 13, 2014, in connection with the 2014 Debt Securitization and the offering of the 2021 Asset-Backed Notes by Hercules Capital Funding Trust 2014-1 (the “2014 Securitization Issuer”), we sold and/or contributed to Hercules Capital Funding 2014-1 LLC, as trust depositor (the “2014 Trust Depositor”), certain senior loans made to certain of our portfolio companies (the “2014 Loans”), which the 2014 Trust Depositor in turn sold and/or contributed to the 2014 Securitization Issuer in exchange for 100% of the equity interest in the 2014 Securitization Issuer, cash proceeds and other consideration. Following these transfers, the 2014 Securitization Issuer, and not the 2014 Trust Depositor or us, held all of the ownership interest in the 2014 Loans.