Supermicro appoints former Western Digital exec Mark Long as new CFO

SMCI named Mark Long Senior Vice President and Chief Financial Officer effective immediately on October 15, 2026. The company said Long reports directly to CEO Charles Liang. An SEC filing shows the board made the appointment and that David Weigand ceased serving as CFO. The company said Weigand will assist in the transition and shift his focus to helping optimize and accelerate the business, and the filing does not say whether he is leaving the company.

Long is a former executive of WDC. Per the filing he was Western Digital's chief financial officer from 2016 to 2019 and its chief strategy officer from 2015 to 2019. Since 2019 he has been a principal at Prime Impact Capital, an early-stage investment and advisory firm, and from 2020 to 2023 he was co-CEO and CFO of a public SPAC, Prime Impact Acquisition I. The company's release also lists earlier roles in strategy at Hitachi Global Storage Technologies and in investment banking focused on software, cloud infrastructure and storage. His offer letter provides an annual base salary of $725,000 and a sign-on bonus of $500,000.

Shares reacted negatively. Investing.com reported that SMCI tumbled more than 8% in early U.S. trading, but attributed the drop mainly to the broader semiconductor market selloff rather than the appointment itself. No closing price was found in the sources reviewed. The same report said the company began seeking a new finance chief following a third-party accounting review, and the filing states no disagreement with the company.

Investors may watch how Long approaches financial reporting and controls, and whether the stock separates from broader semiconductor moves in the coming sessions.