Nvidia shares closed down more than 4% after the abrupt resignation of Chief Executive Officer Jensen Huang. CoreWeave, which is closely tied to Nvidia, also weakened.

In regular U.S. trading on Nov. 12, Nvidia fell 4.34% from the previous session to close at $166.19. Huang stepped down effective immediately, bringing concerns about a leadership vacuum and uncertainty over the company’s artificial intelligence strategy into focus.

Nvidia appointed Chief Financial Officer Colette Kress as interim CEO and is searching for a successor. Bernstein analyst Stacy Rasgon downgraded the stock to hold to reflect the risks tied to the management change. He also cut his price target to $200 from $400.

CoreWeave closed down 6.86% at $56.60 the same day. The move reflected uncertainty stemming from the leadership change at Nvidia. Nvidia owns about a 13% stake in CoreWeave and is also a key semiconductor supplier to the company.

Super Micro Computer, separately from the Nvidia resignation news, plunged 11.30% to close at $26.99. News reports said the U.S. Department of Justice is investigating allegations that Super Micro Computer products were illegally shipped to China. The probe is focused on individuals linked to Megaspeed in Singapore.