Where America’s most prominent short-sellers are placing their bets

Illustration: Julia Dufosse

Dec 16th 2025|6 min read

“I have to giggle,” says Jim Chanos, asked if investors have become overly optimistic about artificial intelligence. “We’ve got to the ‘data-centres-in-space’ stage of the cycle.” Firms from SpaceX and Blue Origin to Alphabet plan to shrug off earthly constraints on the computing clusters that power AI, and launch them into orbit. To Mr Chanos, who is perhaps Wall Street’s most experienced short-seller, such pharaonic ambitions immediately ring alarm bells. Yet even he hesitates to say definitively that share prices are in a bubble: “That’s something we’ll only be able to tell with hindsight.”