Huang, 63, has no obvious successor. He owns about 3.6% of Nvidia's stock and has dozens of direct reports, a span of control that has kept decision-making tightly in his hands.
Reached by the New York Times, Huang said,"I don't think you should be talking to me directly."He then hung up, the newspaper reported.
The turmoil comes days before investors are due to hear the company's financial results and outlook. Quarterly results are scheduled for November 17.
Odds on the prediction-market site Polymarket moved sharply, showing an 88% chance that Huang would resign or be removed by the end of the year. Among possible successors, the odds favoured Ian Buck, who oversees the business that serves Nvidia's data-centre clients.
Huang also faces a potential congressional subpoena if he does not answer a request for a closed-door briefing on allegations of an affair with a Chinese spy. Reuters could not immediately verify the report.
Nvidia did not immediately respond to a request for comment on the board meeting. Nvidia and Powell did not immediately respond to separate requests for comment.
Investors and analysts said demand for Nvidia's chips was unlikely to fall in the near term. They said the wider group of companies backed by Nvidia — largely customers building data centres that will use its chips — might suffer.
The board's shift, from a public vote of confidence on Sunday to a meeting that could end Huang's tenure, leaves investors with little clarity on who would run the company if directors act.
Any removal would test a business built around one executive just as customers, rivals and governments are competing for the chips that power artificial-intelligence systems.
Until directors vote, Huang remains chief executive of the company he has run since its early years, with no named heir and a results report days away.