Shea Thomas Anthony sold OS

Footnotes

Pursuant to the Merger Agreement, at the Effective Time, each share of Class D Common Stock was cancelled and converted into the right to receive the Per Share Price, without interest, less applicable withholding taxes.; Pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated January 6, 2026, by and among OneStream, Inc. ("Issuer"), OneStream Software LLC, a subsidiary of Issuer ("Company LLC"), Onward AcquireCo Inc. ("Parent"), Onward Merger Sub 2, LLC ( "Merger Sub I") and Onward Merger Sub, Inc. ("Merger Sub II"), on April 1, 2026, Merger Sub 1 merged with and into Company LLC (the "First Merger"), with Company LLC surviving the First Merger and becoming a subsidiary of Parent, and Merger Sub II merged with and into Issuer (the "Second Merger" and together with the First Merger, the "Mergers"), with Issuer surviving the Second Merger and becoming a subsidiary of Parent.; Shares held of record by the Shea Family Trust dated December 25, 2019 (the "2019 Shea Family Trust"). The Reporting Person's spouse serves as the co-trustee for the 2019 Shea Family Trust. By virtue of his relationship, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares held by the 2019 Shea Family Trust.