Among individual movers, SoundHound SOUN rallied 30% after the voice AI platform provider posted a more than 200% leap in second-quarter revenue, to a record $42.7 million. It also raised its full-year midpoint sales outlook to $169 million, up from $167 million. Its loss of 3 cents per share narrowed from the year-earlier quarter.

Investors were focused on President Trump's tariff policy on Thursday as the president unveiled plans for new chips tariffs that included exemptions for companies building in the U.S., or that have committed to build.

Apple's stock surge on Wednesday added $153 billion in market capitalization to the iPhone maker, its eighth biggest one-day gain on record. Wednesday's market-cap gain was larger than the individual market caps of the smallest 435 companies in the S&P 500 index,