Alphabet's 12% slump drags Nasdaq futures down 2.3%

Alphabet had been under pressure to at least meet analysts' expectations for growth, as concerns mounted over how much it is spending to invest in artificial intelligence. The weaker summer growth it reported fed directly into that worry, and the stock's more than 12% slide on Thursday marked its worst day since it began trading more than 20 years ago.

The pain was not confined to Alphabet. Futures for the Nasdaq declined 2.3% on Friday, and AI-related stocks have been volatile—rising on enthusiasm for the technology, then falling on concerns such as supply constraints. Amazon and Intel also moved lower in premarket trading after their own cautious outlooks, adding to the pressure on Wall Street.

The broader market backdrop included a roughly 3% drop in Bitcoin to $77,695 following a $6.36 billion hack at Binance, and energy prices rose, with U.S. crude up 2.1% to $104.13 a barrel.