Secretive trading giant lost $15 billion in one month
Jane Street, a trading giant operating under the radar with sophisticated algorithms, lost a massive sum in July, much of it from investments in a collapsed AI fund. Despite this, it has recorded enormous revenues since the beginning of the year.
One of the most successful and secretive firms on Wall Street, Jane Street, suffered an unusual blow last month when it recorded a loss of approximately $15 billion — the worst month in its history and, according to company reports, the first month to record a loss since 2016.
Jane Street is not a traditional investment bank. The company, founded in 1999, uses algorithms, mathematical models, and high-speed trading systems to provide liquidity in markets around the world and execute trades in massive volumes. It operates in more than 200 trading venues and does so with minimal media exposure. Although it is not known to the general public, it is considered one of the most profitable on Wall Street.
A significant part of the loss is linked to Jane Street's exposure to Situational Awareness — a hedge fund that focused on aggressive bets on companies in the field of artificial intelligence. The fund, founded by 25-year-old Leopold Aschenbrenner, grew rapidly and reached a valuation of tens of billions of dollars. However, when technology and AI stocks began to fall, the fund's high leverage became a problem: it was required to sell assets quickly following margin calls, and these sales deepened the declines until eventually its remnants were sold to Citadel.
The event also hit Jane Street, which held significant exposure to the fund, and simultaneously suffered losses from other positions in technology stocks, especially in Asia. Exceptionally, its hedging strategies failed to prevent the damage.
Despite the huge loss, Jane Street has already generated more than $40 billion from trading since the beginning of 2026, more than all its revenue in 2025.
