Rebounding tech stocks are driving U.S. indexes higher Tuesday, a day after they tumbled on doubts about whether the artificial-intelligence frenzy really needs all the dollars being poured into it. The S&P 500 was 1% higher in late trading and clawing back nearly two-thirds of its earlier drop.

Nvidia Corp., the poster child of the AI frenzy, sank 17 per cent and headed toward the biggest market-cap loss for a single stock in market history. The AI leader wiped of $500 billion of its market value and shed 21 per cent off its stock price in two days.

Nvidia shares' 9% recovery Tuesday was the second-best day in terms of market cap added for any company ever, trailing only a record it set in July.