A source familiar with the matter has revealed that Jane Street suffered its first monthly loss in nearly a decade, totaling approximately $15 billion, as the hedge fund Situational Awareness, which focuses on artificial intelligence, stumbled and dragged down asset prices across the broader equity market.

The market turmoil has inflicted a rare and severe loss on Jane Street, which invested in Situational Awareness and AI-related companies. The source, who requested anonymity, indicated that the firm's investment in the hedge fund, combined with missteps in Asian equity markets, contributed to the losses.

"July was a terrible month," Jane Street partner Turner Batty said in an internal memo. Despite this, the source noted that the company has generated over $40 billion in net trading revenue year-to-date, already surpassing the all-time Wall Street record it set for the full year of 2025.

Reports indicate that the market maker described the impact of Situational Awareness's steep decline while seeking to refinance over $10 billion in debt. The losses at Jane Street were first reported by the financial press.