Leopold Aschenbrenner’s wedding came after a disastrous month for his Situational Awareness hedge fund, which had suffered heavy losses and forced a sale of positions. His fall from grace also impacted Rob Granieri, the 54-year-old co-founder of Jane Street Capital, a premier Wall Street trading firm. Jane Street had heavily invested in Aschenbrenner’s AI-focused fund and positions in AI-linked stocks like Sandisk, Nebius, and Bloom Energy, contributing to a massive $15bn loss in trading revenues during July’s sector sell-off.

This was a stunning reversal for Jane Street, whose returns had long been the envy of Wall Street. The firm, once a nimble market maker profiting from tiny price differentials, now takes massive, long-horizon bets, increasing risk to its balance sheet and regulators. Larry Tabb of Bloomberg Intelligence noted that longer holding periods reduce clarity on the future.

Jane Street admitted in an August letter that short-term hedges provided little help against AI stock losses. Unlike other hedge funds, Jane Street is proprietary, with profits and losses shared among senior staff. The firm’s shift reflects its meteoric growth, trading gains reaching $40bn in 2025, and a growing warehouse of positions it cannot easily close.

Paul Rowady of Alphacution said the firm is now a ‘different animal’ trading slower with bigger positions.