On December 18, 2025, the board of directors (the "Board") of Bain Capital GSS Investment Corp. (the "Company") appointed Michael E. Purves to the Board to serve as an independent director of the Board, effective immediately. Mr. Purves will also serve on the Company's Audit Committee, Compensation Committee and Nominating Committee of the Board.

Mr. Purves, 61, is the Chief Executive Officer of Tallbacken Capital Advisors, LLC, which he has managed and operated since 2019. Mr. Purves has over 27 years of financial services experience and spent the first 12 years of his career in investment banking. Mr. Purves received a BA from Columbia University and an MBA from the Wharton School of the University of Pennsylvania.

Mr. Purves owns 30,000 Class B ordinary shares of the Company.

There is no arrangement or understanding between Mr. Purves and any other person pursuant to which Mr. Purves was selected as a director. The Board has determined that Mr. Purves is independent and has no material direct or indirect interest in a related party transaction, which requires disclosure pursuant to Rule 404(a) of Regulation S-K.