OPPENHEIMER HOLDINGS INC

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2025

OR

For the transition period from to

Commission file number 1-12043

(Exact name of registrant as specified in its charter)

Registrant's Telephone number, including area code: (212)668-8000

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

Not Applicable

(Title of class)

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yeso No x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yeso No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x Noo

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes x Noo

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act. (Check one):

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C.7262(b)) by the registered public accounting firm that prepared or issued its audit report. x

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. o

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). o

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yeso Nox

The aggregate market value of the voting stock of the Company held by non-affiliates of the Company cannot be calculated in a meaningful way because there is only limited trading in the class of voting stock of the Company. The aggregate market value of the Class A non-voting common stock held by non-affiliates of the Company at June 30, 2025 was $685.2 million based on the per share closing price of the Class A non-voting common stock on the New York Stock Exchange on June 30, 2025 of $65.77.

The number of shares of the Company's Class A non-voting common stock and Class B voting common stock (being the only classes of common stock of the Company) outstanding on February 26, 2026 was 10,607,590 and 99,665 shares, respectively.

DOCUMENTS INCORPORATED BY REFERENCE

The Company's definitive Proxy Statement for the 2026 Annual Meeting of Stockholders to be filed by the Company pursuant to Regulation 14A is incorporated into Items 10, 11, 12, 13 and 14 of Part III of this Form 10-K.