Coalition, which only gives revenue figures for the top-ranked bank in categories including equities and advisory, said that JPMorgan's investment banking revenue in the first quarter fell by almost 15 percent from $6.9 billion in the same period last year.
Most investment banks have seen trading revenues slump over the past year amid a low interest rate environment and tougher regulations requiring them to hold more capital, which have driven down returns.
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A number are reducing their operations and cutting jobs as a result.
Barclays said last month 7,000 jobs are to go at its investment bank and the head of investment banking at JPMorgan, Daniel Pinto, recently told Reuters that the bank would be "laser-focused" on cost cutting.
Coalition said turnover at JPMorgan's fixed income, commodities and currencies (FICC) division was $3.2 billion in the January to March period, down by more than a quarter from the previous year. The figure was enough to keep it in the top spot in Coalition's league table in FICC, alongside Deutsche Bank and Citi.