Alphabet fell after the company said it would buy Wiz for about $32 billion in its biggest deal as the Google parent doubles down on cybersecurity.
Nvidia shares declined. The company is expected to reveal details of its latest AI chip at its annual software developer conference.
Tesla slumped after brokerage RBC slashed its price target on the EV maker's stock to $120 from $320, citing reduced expectations for its full self-driving pricing and robotaxi market share. Its shares are now down nearly 45% on the year.
Reflecting the defensive tone, investors moved to safe-haven assets, with gold trading at a record high, after crossing $3,000 per ounce for the first time last week.