Graham Holdings Company Reports 8.9% Stake in PubMatic, Inc. via Amended Schedule 13G

Graham Holdings Company has filed a Schedule 13G/A (Amendment No. 2) with the SEC, reporting a significant position in PubMatic, Inc. (PUBM). As of the event date on March 31, 2026, the filer reported beneficial ownership of 3,398,904 shares of Class A Common Stock. This represents an 8.9% ownership stake in the company, based on approximately 38.18 million shares outstanding as of late April 2026. The filing indicates that Graham Holdings Company maintains sole voting and dispositive power over all 3,398,904 shares. Compared to previous data showing zero holdings, this reflects a substantial increase in their investment position. The filer, a Delaware-incorporated entity based in Arlington, VA, certified that the shares were acquired in the ordinary course of business and not for the purpose of changing or influencing the control of the issuer. This passive investment filing highlights Graham Holdings' continued interest in the digital advertising technology sector through its stake in PubMatic.