GLADSTONE CAPITAL CORP 8-KCurrent Reports (8-K / ad hoc)

Market for Equity / Stockholders

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. On October 1, 2026, the appointment of Michael McQuigg as President of Gladstone Capital Corporation (the “Company”), which was previously announced on March 23, 2026, became effective. As of the same date, Robert Marcotte stepped down as President of the Company and continues to serve as its Chief Executive Officer. Mr. McQuigg, age 48, has served as the Company’s Executive Vice President and Senior Managing Director since 2021, where he focused on the origination and management of middle market debt and equity investments supporting both private equity sponsors and owner operators. Mr. McQuigg joined the Gladstone Companies in April 2015. Previously, Mr. McQuigg was a Principal at Deerpath Capital focusing on private debt and equity investments in lower middle market companies and was also with H.I.G. Capital, where he focused on control and minority equity investments in the lower middle market. Mr. McQuigg received his Master of Business Administration from Columbia Business School and his Bachelor of Arts from Johns Hopkins University. Mr. McQuigg serves on the Dean’s Advisory Board for the Krieger School of Arts & Sciences at Johns Hopkins University, and on the Advisory Council for the Center for Financial Economics. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. Dated: October 1, 2026 GLADSTONE CAPITAL CORPORATION By: /s/ Nicole Schaltenbrand Nicole Schaltenbrand Chief Financial Officer & Treasurer