Jane Street, the Wall Street quant trader, suffered a stunning $15bn loss in trading revenues this year after heavy bets on AI-linked stocks and a stake in Leopold Aschenbrenner's Situational Awareness fund soured during a July sector sell-off. The loss marked the first monthly decline in a decade for the firm, whose revenue had nearly doubled to $40bn in 2025. The FT spoke to over a dozen current and former employees and analysts who detailed the firm's evolution from a nimble market maker into one of the largest US financial institutions taking massive, longer-horizon bets. "When you start seeing the kind of revenue these guys are putting up, the only way that's possible is when your holding period extends as well as the size," said Larry Tabb of Bloomberg Intelligence. Paul Rowady of Alphacution noted the firm is now "a different animal" with slower trading and bigger positions absorbing more capital. Jane Street declined to comment. Regulators are closely watching firms of this scale for potential market dislocations.

Separately, investors in Neil Woodford's collapsed flagship fund still seek answers a decade later. Ian Duffield, who lost over £10,000, called Woodford "an arrogant, egotistical man who has never properly taken responsibility for his misbehaviour." The 2019 collapse continues to confound those who once viewed him as the UK's answer to Warren Buffett. Meanwhile, asset management M&A activity is booming.