Big tech stocks falter as investors question whether billions being poured into AI can generate returns quickly enough

A sell-off of tech stocks that began earlier this month and gained steam with disappointing earnings from leading tech companies drove US markets down by hundreds of billions of dollars Friday. In total, the decline has knocked nearly $1tn in value off the tech-heavy Nasdaq exchange in one week and erased about $2tn in a month.

The S&P 500, the index of the 500 most valuable companies in the US, fell by more than 1% Friday, losing hundreds of billions of dollars in market value. It was on track to erase its gain for October, even though it set its all-time high during the same month. The weakness for technology stocks dragged the Nasdaq composite down even further, more than 3%, also erasing hundreds of billions in value. The Down Jones Industrial Average fell less.

Big tech stocks falter as investors question whether billions being poured into AI can generate returns quickly enough

A sell-off of tech stocks that began earlier this month and gained steam with disappointing earnings from leading tech companies drove US markets down by hundreds of billions of dollars Friday. In total, the decline has knocked nearly $1tn in value off the tech-heavy Nasdaq exchange in one week and erased about $2tn in a month.

The S&P 500, the index of the 500 most valuable companies in the US, fell by more than 1% Friday, losing hundreds of billions of dollars in market value. It was on track to erase its gain for October, even though it set its all-time high during the same month. The weakness for technology stocks dragged the Nasdaq composite down even further, more than 3%, also erasing hundreds of billions in value. The Down Jones Industrial Average fell less.

As thousands of datacentres are constructed across Europe, the Guardian and Investigate Europe have uncovered disturbing evidence that some workers building them are exposed to dangerous conditions and living in fear of speaking out

Sandu* checked his watch. He was winding down the last 15 minutes of his shift at a vast Google datacentre site in Saint-Ghislain, Belgium, in March, when the call came in. The 34-year-old electrical tester had already worked almost 10 hours, but says such last-minute jobs were normal: “I had no choice. People have been fired after saying no.”

The task was one Sandu had done many times before and involved a series of tests measuring the safety and integrity of the electrical wiring. A protective suit was locked away in an equipment room. The round trip would have added another 15 minutes to the job, he says, and people were waiting, so he decided not to retrieve the suit.

As thousands of datacentres are constructed across Europe, the Guardian and Investigate Europe have uncovered disturbing evidence that some workers building them are exposed to dangerous conditions and living in fear of speaking out

Sandu* checked his watch. He was winding down the last 15 minutes of his shift at a vast Google datacentre site in Saint-Ghislain, Belgium, in March, when the call came in. The 34-year-old electrical tester had already worked almost 10 hours, but says such last-minute jobs were normal: “I had no choice. People have been fired after saying no.”

The task was one Sandu had done many times before and involved a series of tests measuring the safety and integrity of the electrical wiring. A protective suit was locked away in an equipment room. The round trip would have added another 15 minutes to the job, he says, and people were waiting, so he decided not to retrieve the suit.

Net profit slid 25% from a year earlier to $26.2bn, well short of expectations, though revenue rose to $127.6bn

Shares in the Google parent Alphabet fell double digits Wednesday evening into Thursday trading, erasing hundreds of billions of dollars in stock market value from the $4tn tech giant.

The company had reported lower-than-expected profit and a slowdown in its advertising business while it maintained big spending on AI.