西南资本美股招股说明书(2026-02-02版)

Supplement No.5, dated February 2, 2026toProspectus, dated October 29, 2024 and This supplement amends, supplements or modifies certain information contained in the prospectus supplement, dated October 30, 2024 (the“ATM Prospectus Supplement”), and the accompanying prospectus, dated October 29, 2024 (the “Base Prospectus,” and together with theATM Prospectus Supplement and the documents deemed incorporated by reference in each, the “Prospectus”), which relate to the sale ofshares of common stock of Capital Southwest Corporation in an “at-the-market” offering (the “ATM Program”) pursuant to those certain (i)third amended and restated equity distribution agreements, each dated May 26, 2021 and as amended from time to time, with each ofJefferies LLC (“Jefferies”) and Raymond James & Associates, Inc. (“Raymond James”) and (ii) amended and restated equity distributionagreements, each dated May 26, 2021 and as amended from time to time, with each of Citizens JMP Securities, LLC (f/k/a JMP SecuritiesLLC) (“Citizens Capital Markets”) and B. Riley Securities, Inc. (“B. Riley” and, together with Jefferies, Raymond James and CitizensCapital Markets, the “Sales Agents”). The terms the “Company,” “CSWC,” “we,” “us,” and “our” refer to Capital Southwest Corporation You should carefully read the entire Prospectus and this supplement before investing in our common stock. This supplement should be readin conjunction with the Prospectus.You should also carefully consider the information set forth under the sections entitled “Risk Factors”on page S-9 of the ATM Prospectus Supplement, page 10 of the Base Prospectus and in our Annual Report on Form 10-K for the fiscal STATUS OF THE "AT-THE-MARKET" OFFERING From March 4, 2019 to December 31, 2025, we sold a total of 39,333,069 shares of our common stock under the ATM Program for grossproceeds of approximately $844.6 million and net proceeds of approximately $829.6 million, after deducting commissions to the Sales FEES AND EXPENSES The following table is intended to assist you in understanding the costs and expenses you will bear directly or indirectly. We cautionyou that some of the percentages indicated in the table below are estimates and may vary. Except where the context suggests otherwise,whenever there is a reference to fees or expenses paid by “you,” “us” or “CSWC,” or that “we” will pay fees or expenses, you will indirectly Shareholder Transaction Expenses: (1)Represents the Sales Agents’ commission with respect to the shares of common stock being sold in this offering. There is no guarantee that there will be anyadditional sales of our common stock pursuant to the Prospectus. (2)The percentage reflects estimated offering expenses for this offering of approximately $2,500,000, of which we have incurred $2,070,000 as of January 29, 2026,and assumes that we sell all $1.0 billion of shares of common stock available under the equity distribution agreements with the Sales Agents. (3)The expenses of administering our dividend reinvestment plan (“DRIP”) are included in operating expenses. The DRIP does not allow shareholders to sell sharesthrough the DRIP. If a shareholder wishes to sell shares they would be required to select a broker of their choice and pay any fees or other costs associated with thesale. (4)Operating expenses in this table represent the estimated annual operating expenses of CSWC and its consolidated subsidiaries based on actual operating expenses forthe quarter ended December 31, 2025. We do not have an investment adviser and are internally managed by our executive officers under the supervision of our boardof directors. As a result, we do not pay investment advisory fees, but instead we pay the operating costs associated with employing investment management available commitments of $510 million under the Company's senior secured revolving credit facility (the “Corporate Credit Facility”) and available commitments of$200 million under the Company's special purpose vehicle financing credit facility (the “SPV Credit Facility”), and our anticipated drawdowns from our creditfacilities, (b) our actual interest rate terms under the SBA-guaranteed debentures issued by each of Capital Southwest SBIC I, LP and Capital Southwest SBIC II, LP(the "SBA Debentures") and our anticipated drawdowns of the SBA Debentures, and (c) our estimated annual interest payments, based on actual interest rate terms,on the 5.125% convertible notes due 2029 (the "2029 Convertible Notes") and the 5.950% notes due 2030 (the “September 2030 Notes”). As of December 31, 2025,we had $210.0 million in borrowings outstanding under our Corporate Credit Facility, $104.0 million outstanding under our SPV Credit Facility, $195.0 million taxes. Deferred taxes are non-cash in nature and may vary significantly from period to period. We are required to include deferred taxes in calculating our annualexpenses even though deferred taxes are not currently payable or receivable. Income tax prov