Nvidia stock briefly touched a new record Tuesday following a high-profile speech from its billionaire leader Jensen Huang, but surprisingly reversed quickly to a significant daily loss, headlining a surprise stark selloff across technology stocks.

Uber drove 3.2% higher after the ride-hailing app said it would accelerate $1.5 billion in purchases of its own stock, part of a previously announced $7 billion buyback program. Uber’s chief financial officer, Prashanth Mahendra-Rajah, said it’s making the move because its stock price looks cheap compared with the strength of its business.