OPPENHEIMER HOLDINGS INC 10-Q

Item 5. OTHER INFORMATION During the period covered by this Quarterly Report on Form 10-Q, no director or officer of the Company adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K. 56 Table of Contents Item 6. EXHIBITS 31.1 * Certification of Robert S. Lowenthal 31.2 * Certification of Brad M. Watkins 32 ** Certification of Robert S. Lowenthal and Brad M. Watkins 101 * Interactive data files pursuant to Rule 405 of Regulation S-T (unaudited): (i) the Condensed Consolidated Balance Sheets as of September 30, 2025 and December 31, 2024, (ii) the Condensed Consolidated Income Statements for the three and nine months ended September 30, 2025 and 2024, (iii) the Condensed Consolidated Statements of Comprehensive Income for the three and nine months ended September 30, 2025 and 2024, (iv) the Condensed Consolidated Statements of Changes in Stockholders' Equity and Noncontrolling Interests for the three and nine months ended September 30, 2025 and 2024, (v) the Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2025 and 2024, and (vi) the notes to the Condensed Consolidated Financial Statements. 104* Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101) * Filed herewith. ** Furnished herewith. 57 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, thereunto duly authorized. OPPENHEIMER HOLDINGS INC. Signed at New York, New York, this 31st day of October, 2025 By: /s/ Robert S. Lowenthal Robert S. Lowenthal, President and Chief Executive Officer (Principal Executive Officer) By: /s/ Brad M. Watkins Brad M. Watkins, Chief Financial Officer (Principal Financial and Accounting Officer) 58