Two of China’s best-known hedge fund managers are warning that the artificial intelligence boom in global stock markets has become an unsustainable bubble.

Wealspring Asset, whose founder Yang Dong is well-known in China for calling the top in 2007, said global AI stocks have become a “super bubble” and that the “collapse point may not be far away,” according to an investor letter seen by Bloomberg News. Shanghai Banxia Investment Management Center said “the trigger for the AI bubble to burst has already appeared,” citing pressure on breakneck revenue growth at Anthropic PBC.