Bain Capital Specialty Finance, Inc.

n

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

For the quarterly period ended September 30,2025

OR

For the transition period from __ to __

Commission file number:814-01175

BAIN CAPITAL SPECIALTY FINANCE, INC.

(Exact Name of Registrant as Specified in its Charter)

(617)516‑2000

(Registrant’s Telephone Number, Including Area Code)

Former Name, Former Address and Former Fiscal Year, if Changed Since Last Report: N/A

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b‑2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b‑2 of the Exchange Act). Yes ☐ No☒

As of November 10, 2025, the registrant had 64,868,507 shares of common stock outstanding.

TABLE OF CONTENTS

i

FORWARD-LOOKING STATEMENTS

Statements contained in this Quarterly Report on Form 10-Q (the “Quarterly Report”) (including those relating to current and future market conditions and trends in respect thereof) that are not historical facts are based on current expectations, estimates, projections, opinions and/or beliefs of the Company, BCSF Advisors, LP (the “Advisor”) and/or Bain Capital Credit, LP and its affiliated advisers (collectively, “Bain Capital Credit”). Such statements involve known and unknown risks, uncertainties and other factors and undue reliance should not be placed thereon. Certain information contained in this Quarterly Report constitutes “forward-looking statements,” which can be identified by the use of forward-looking terminology such as “may,” “will,” “should,” “seek,” “expect,” “anticipate,” “project,” “estimate,” “intend,” “continue,” “target,” or “believe” or the negatives thereof or other variations thereon or comparable terminology. Due to various risks and uncertainties, actual events or results or the actual performance of the Company may differ materially from those reflected or contemplated in such forward-looking statements. These statements are not guarantees of future performance and are subject to risks, uncertainties, and other factors, some of which are beyond our control and are difficult to predict, that could cause actual results to differ materially from those expressed or forecasted in the forward-looking statements including, without limitation, the risks, uncertainties and other factors we identify in the section entitled Part I, “Item 1A. Risk Factors” in our Annual Report on Form 10-K (the “Annual Report”) for the fiscal year ended December 31, 2024 and in our filings with the Securities and Exchange Commission (the “SEC”).

Although we believe that the assumptions on which these forward-looking statements are based are reasonable, some of those assumptions may be based on the work of third parties and any of those assumptions could prove to be inaccurate; as a result, the forward-looking statements based on those assumptions also could prove to be inaccurate. In light of these and other uncertainties, the inclusion of a projection or forward-looking statement in this Quarterly Report should not be regarded as a representation by us that our plans and objectives will be achieved. These risks and uncertainties include those described or identified in the section entitled Part I, “Item 1A. Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024. Investors should not place undue reliance on these forward-looking statements, which apply only as of the date of this Quarterly Report. We do not undertake any obligation to update or revise any forward-looking statements or any other information contained herein, except as required by applicable law. The safe harbor provisions of Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), which preclude civil liability for certain forward-looking statements, do not apply to the forward-looking statements in this Quarterly Report because we are an investment company.

ii