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

Warning from OpenAI’s Sam Altman and MIT paper puncture Wall Street’s enthusiasm

“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