Nvidia stock was gyrating between losses and gains Tuesday, after the artificial-intelligence chip maker’s had a bad start to the week. Shares rose .85% to $107.89 in afternoon trading, while the S&P 500 sank 1.

President Donald Trump announced a major artificial intelligence initiative, partnering with tech giants OpenAI, Nvidia (NVDA), Oracle (ORCL), and SoftBank (SFTBY) to invest up to $500 billion in domestic AI infrastructure over the next four years.

Shares of some of the biggest semiconductor players, including Nvidia Corp. (NVDA), Advanced Micro Devices Inc. (AMD), and Broadcom Inc. (AVGO), among others, surged by as much as 6% on Wednesday even as U.