Blythe Masters, the British woman who runs JPMorgan's commodities division, has steered the department to record turnover exceeding $2.8bn (£1.8bn) in 2011, more than long-time industry leaders Goldman Sachs and Morgan Stanley.
Reuters research shows that Cambridge-educated Ms Masters beat her arch-rival, Isabelle Ealet at Goldman Sachs in London, whose commodities division's revenues stagnated at $1.6bn. JPMorgan's performance, a threefold leap in revenues, is a huge bounceback for one of the most powerful women on Wall Street.
In 2010 there had been serious concerns about staff defections and sluggish growth, but Ms Masters, who started at the bank aged 18 as an intern in London, had the firm backing of the chief executive, Jamie Dimon, and investment banking head, Jes Staley. He praised her for being "one tough kid" and stuck with her.
Ms Masters gained notoriety for pioneering credit default swaps, blamed by many for the financial crisis. She acknowledged in a 2008 speech that she had been branded "the woman who created weapons of mass destruction", although she defends the products, saying the people using them were at fault.
Ms Masters built the bank's commodities business through acquisitions including the takeover in 2010 of Royal Bank of Scotland's Sempra Commodities, a large trader of natural gas.
By contrast, rivals have stumbled lately, with Morgan Stanley's revenues shrinking for a third consecutive year, the worst streak since at least 1995, and Goldman Sachs' commodity unit nursing a large drop in revenues since raking in more than $4.5bn in 2009.
The blunt-speaking Ms Masters told staff in 2010 rivals were "scared shitless of us", adding: "They'd better be. This is a platform that's going to win."
Ms Ealet was promoted out of Goldman's commodities unit in January.