JPMorgan Chase made $907 million in pretax profit from deposits held at the bank by imprisoned Ponzi scheme operator Bernard L. Madoff, a study said.

The Madoff firm’s balances in its JPMorgan account generated the profit from 1986 to 2008, according to Linus Wilson, an assistant finance professor at the University of Louisiana at Lafayette.

Joseph Evangelisti, a JPMorgan spokesman, declined to comment.