Shares in US tech stocks are falling but it would probably be unwise for fund managers to pull out

Shock sell-off after study warns most investments in artificial intelligence get zero returns

“The crash is separating real AI revenues from companies that only have AI PowerPoints.”

Investors’ long-running enthusiasm for artificial intelligence showed signs of faltering on Tuesday as tech stocks tumbled.

The US stock market has seen $1 trillion wiped off in four days as a sell-off in tech companies deepened on Wednesday.

Shares in US tech stocks are falling but it would probably be unwise for fund managers to pull out