The Nasdaq could face market-cap losses of nearly $1 trillion if premarket declines hold into the close of trading.

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.