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.

Tuesday’s session followed a start to the week that marked Nvidia’s worst day in years, as a roughly 17% drop led to a loss of nearly $600 billion in market value.

Shares of Nvidia ( NVDA 8.93%) surged higher on Tuesday, after taking it on the chin Monday. The maker of graphics processing units (GPUs) used for artificial intelligence (AI) applications gained as much as 7.2%. As of 1:30 p.m. ET, the stock was still up 7.1%.