Sixth Street Specialty Lending (TSLX) amends proxy to fix director share counts

Rhea-AI Filing Summary

Sixth Street Specialty Lending, Inc. filed Amendment No. 1 to its proxy statement to correct the Security Ownership of Certain Beneficial Owners and Management table. The amendment restates holdings as of March 31, 2026 and confirms 95,019,600 shares outstanding as of that date.

The amendment corrects individual director share counts (for example, Joshua Easterly 65,790 shares, Ronald Tanemura 85,516 shares) and reports All directors and officers as a group: 3,640,068 shares (3.83%). The filing states there is no change to the total number of shares held by all directors and officers as a group.

Insights

Corporate Governance Counsel

Amendment corrects director-level ownership disclosures without changing group totals.

The amendment restates the "Security Ownership" table to correct individual director holdings as of March 31, 2026. It affirms the aggregate group figure of 3,640,068 shares (3.83%) and the company-wide outstanding share count of 95,019,600.

These corrections are procedural in nature; disclosure accuracy ahead of a stockholder vote is the core issue. Subsequent filings or meeting materials should be checked for any further post- updates.

Key Figures

Shares outstanding: 95,019,600 shares Directors and officers as a group: 3,640,068 shares Joshua Easterly: 65,790 shares +3 more

6 metrics

Shares outstanding 95,019,600 shares as of March 31, 2026

Directors and officers as a group 3,640,068 shares aggregate holdings; 3.83% as of March 31, 2026

Joshua Easterly 65,790 shares director holding as of March 31, 2026

Ronald Tanemura 85,516 shares director holding as of March 31, 2026

Michael Fishman 36,366 shares director nominee holding as of March 31, 2026

All directors and officers (count) 18 persons group count reported in ownership table

Key Terms

Beneficial ownership, Schedule 13D or Schedule 13G, Proxy Statement

3 terms

Beneficial ownership regulatory

"Beneficial ownership is determined in accordance with the rules and regulations of the U.S. Securities and Exchange Commission"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

Schedule 13D or Schedule 13G regulatory

"Based upon Schedule 13D or Schedule 13G filings with the SEC, the Company is not aware of any person that beneficially owns 5% or more"

Proxy Statement regulatory

"This Amendment No. 1 to Schedule 14A is being filed to amend Sixth Street Specialty Lending, Inc.’s definitive proxy statement"

A proxy statement is a document companies send to shareholders ahead of a meeting that lays out the items up for a vote—like who will sit on the board, executive pay, and major corporate decisions—and provides background so shareholders can decide how to cast their votes or appoint someone to vote for them. Think of it as an agenda plus a ballot and briefing notes, important because the outcomes can change control, strategy, and value.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

(RULE 14a-101)

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. 1)

Filed by the Registrant  ☒

Filed by a Party other than the Registrant  ☐

Check the appropriate box:

☐ Preliminary Proxy Statement

☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

☐ Definitive Proxy Statement

☒ Definitive Additional Materials

☐ Soliciting Material under §240.14a-12

Sixth Street Specialty Lending, Inc.

(Name of Registrant as Specified in Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

☒ No fee required

☐ Fee paid previously with preliminary materials

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11

AMENDMENT NO. 1 TO THE PROXY STATEMENT

DATED APRIL 9, 2026 FOR THE

SPECIAL MEETING OF STOCKHOLDERS TO BE HELD ON MAY 21, 2026

EXPLANATORY NOTE

This Amendment No. 1 to Schedule 14A (“Amendment No. 1”) is being filed to amend Sixth Street Specialty Lending, Inc.’s definitive proxy statement for its 2026 Special Meeting of Shareholders (the “Meeting”), which was filed with the Securities and Exchange Commission on April 9, 2026 (the “Proxy Statement”). This Amendment No. 1 amends the disclosures provided in the section “Security Ownership of Certain Beneficial Owners and Management” as set forth on page 5 of the Proxy Statement in order to correct the amount of shares held by certain directors as of March 31, 2026. There is no change to the total number of shares held by all directors and officers as a group. All other items of the Proxy Statement are incorporated herein by reference without changes.

Except as specifically discussed in this Explanatory Note, this Amendment No. 1 does not otherwise modify or update any other disclosures presented in the Proxy Statement. In addition, this Amendment No. 1 does not reflect events occurring after the date of the Proxy Statement or modify or update disclosures that may have been affected by subsequent events.

CHANGE TO THE PROXY STATEMENT

The information under the heading “Security Ownership of Certain Beneficial Owners and Management” on page 5 of the Proxy Statement is amended and restated to read as follows:

SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

Beneficial ownership is determined in accordance with the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”). These rules generally provide that a person is the beneficial owner of securities if the person has or shares the power to vote or direct the voting thereof, or to dispose or direct the disposition thereof or has the right to acquire these powers within 60 days. The following table sets forth, as of March 31, 2026, the beneficial ownership as indicated in the Company’s books and records of each current director, the nominees for director, the Company’s Named Executive Officers and the Company’s executive officers and directors as a group. Based upon Schedule 13D or Schedule 13G filings with the SEC, the Company is not aware of any person that beneficially owns 5% or more of the outstanding shares of the Company’s common stock.

The percentage ownership is based on 95,019,600 shares of common stock outstanding as of March 31, 2026. To the Company’s knowledge, except as indicated in the footnotes to the table, each of the stockholders listed below has sole voting and/or investment power with respect to shares beneficially owned by such stockholder. Unless otherwise indicated by footnote, the address for each listed individual is 2100 McKinney Avenue, Suite 1500, Dallas, TX 75201.

Name of Individual or Identity of Group		Number of Shares of Common Stock Beneficially Owned				Percent of Common Stock Beneficially Owned
Directors and Executive Officers:
Interested Directors
Joshua Easterly(1)			65,790				*	%
Michael Fishman (Director Nominee)(2)			36,366				*	%
Jennifer Gordon			2,500				*	%
Robert (“Bo”) Stanley (Director Nominee)(3)			24,907				*	%
David Stiepleman(4)			31,418				*	%
Independent Directors
Hurley Doddy (Director Nominee)			27,119				*	%

Name of Individual or Identity of Group		Number of Shares of Common Stock Beneficially Owned				Percent of Common Stock Beneficially Owned
John D. Hershey			25,621				*	%
Richard Higginbotham			29,000				*	%
Judy Slotkin			21,667				*	%
Ronald Tanemura			85,516				*	%
P. Emery Covington			15,000				*	%
Named Executive Officers Who Are Not Directors
Ian Simmonds			6,772				*	%
Michael Graf			7,385				*	%
Anton Brett			500				*	%
All Directors and Officers as a Group (18 persons)(5)(6)			3,640,068				3.83	%

* Represents less than 0.1%.

(1) 18,792 shares of common stock beneficially owned by Mr. Easterly have been pledged as security in connection with a line of credit with a third party financial institution unaffiliated with the Company and are held indirectly through entities for which Mr. Easterly has pass through voting power and no dispositive power. On February 19, 2026, pursuant to the Third Amended and Restated Bylaws of the Company, Joshua Easterly informed the Company of his intention to retire from the Board, effective as of the close of business on May 21, 2026. Accordingly, Mr. Easterly will not run for re-election to the Board at the Meeting. Mr. Easterly’s decision was not a result of any disagreement with the Company on any matter relating to the Company’s operations, policies or practices. (2)All 36,366 shares of common stock beneficially owned by Mr. Fishman have been pledged as security in connection with a line of credit with a third party financial institution unaffiliated with the Company and are held indirectly through entities for which Mr. Fishman has pass through voting power and no dispositive power.

(3) 3,907 shares of common stock beneficially owned by Mr. Stanley have been pledged as security in connection with a line of credit with a third party financial institution unaffiliated with the Company and are held indirectly through entities for which Mr. Stanley has pass through voting power and no dispositive power.

(4) 5,544 shares of common stock beneficially owned by Mr. Stiepleman have been pledged as security in connection with a line of credit with a third party financial institution unaffiliated with the Company and are held indirectly through entities for which Mr. Stiepleman has pass through voting power and no dispositive power.

(5) Includes shares owned by executive officers that are not “Named Executive Officers,” already presented by name in the table above. 64,609 shares of common stock beneficially owned by these other executive officers have been pledged as security in connection with lines of credit with a third party financial institution unaffiliated with the Company.

(6) Sixth Street Specialty Lending Advisers, LLC (the “Adviser”) holds 2,714,226 shares of common stock (the “Sixth Street Specialty Lending Advisers Shares”). The Adviser is managed by Sixth Street Specialty Lending Advisers Holdings, LLC, a Delaware limited liability company, the sole member of the Adviser. Sixth Street Specialty Lending Advisers Holdings, LLC is managed by TSSP Holdco Management, LLC, which is managed by a board of directors, which is currently comprised of Alan Waxman. Mr. Waxman is the CEO of TSSP Holdco Management, LLC. Mr. Waxman disclaims beneficial ownership of the Sixth Street Specialty Lending Advisers Shares except to the extent of his pecuniary interest therein.

Important Notice Regarding the Availability of Proxy Material for the Special Meeting of Stockholders to Be Held on May 21, 2026.

This change to the Proxy Statement in this Amendment No. 1 has been incorporated into the Notice of the Meeting and the Proxy Statement which are available on the internet at www.proxyvote.com. This material is first being distributed to stockholders on or about May 15, 2026, and should be read together with the Proxy Statement.

FAQ

What did Sixth Street Specialty Lending (TSLX) change in the proxy amendment?

The amendment corrected individual director share counts in the ownership table as of March 31, 2026. It restated specific director holdings while confirming the aggregate group total of 3,640,068 shares (3.83%) and 95,019,600 shares outstanding.

Does the amendment change the total shares held by directors and officers?

No. The amendment explicitly states there is no change to the total number of shares held by all directors and officers as a group. It only corrects certain individual director share amounts reported in the table.

What share counts are shown for the company and its officers?

The proxy amendment reports 95,019,600 shares outstanding as of March 31, 2026 and 3,640,068 shares (3.83%) held by all directors and officers as a group, per the amended ownership table.

Where can I view the corrected proxy materials for the May 21, 2026 special meeting?

The corrected Notice and Proxy Statement are available online at www.proxyvote.com. The amendment states the materials were distributed beginning on or about May 15, 2026 and should be read with the Proxy Statement.