Jane Street Loses $15 Billion as AI Fund Bet Implodes

Jane Street, one of Wall Street’s largest quantitative trading firms, has built a formidable earnings record through high-speed market-making and cross-asset strategies. Its setback is notable because it involved exposure to Situational Awareness, a hedge fund that made concentrated bets on AI hardware, as well as unsuccessful Asian equity positions. The episode underscores how crowded AI trades and concentrated outside investments can produce unusually large swings even at a highly profitable trading house.

Jane Street lost about $15 billion in July 2026, its first monthly loss in nearly a decade, after Situational Awareness collapsed and bets on Asian stocks went wrong. The reversal did not erase the firm’s exceptional performance earlier in the year: net trading revenue for the first seven months of 2026 still exceeded $40 billion, surpassing its total for all of 2025. The figures show both the scale of July’s damage and Jane Street’s broader earnings power.