Jamie Dimon, chief executive of JPMorgan Chase, has warned that customers will face more costly credit or be denied certain financial products altogether as a result of tougher regulation.
Mr Dimon is famous for clashing with regulators, including Mark Carney, head of the Financial Stability Board and now governor of the Bank of England, as well as slamming capital rules as "anti-American".
But his latest warning in his annual letter to shareholders was notable for being calmer but more detailed. He said capital and liquidity rules meant the cost of providing revolving credit to clients could increase by up to 60 basis points, forcing banks "to charge more" or simply to consider "whether to make revolvers available to that client".
The cost of trade finance would "increase dramatically" by up to 75 basis points, he wrote. On mortgages, "deserving lower- and middle-income consumers may pay far more ... or, worse yet, they won't be able to get one".
He said "increasingly sophisticated shadow banks" were seizing ground vacated by banks. "Non-bank financial competitors will look at every product we price, and if they can do it cheaper with their set of capital providers, they will," he said.
Mr Dimon discussed the costs of JPMorgan's own regulatory-driven retreat, including from commodities and student lending. It would cut about $3 billion from revenue but with "little impact" – about $300 million – on profits.
The chief executive's own finances were detailed in a regulatory filing that accompanied the letter. Under the prevailing Securities and Exchange Commission methodology Mr Dimon made less money in 2013, $11.8 million, a 37 percent reduction.
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But the SEC's figure only takes into account remuneration actually paid out during the year. JPMorgan's own calculation for the chief executive's pay, which has already been published and includes cash and stock awarded this year but paid out in future years, rose from $11.5 million to $20 million, a controversial increase in light of JPMorgan's vast regulatory problems.
After a year where JPMorgan paid a record $13 billion to settle claims it mis-sold mortgage-backed securities, Mr Dimon channelled Charles Dickens, Martin Luther King and Harvard professor Steven Pinker.
"It was the best of times, it was the worst of times," said Mr Dimon. "We came through it scarred but strengthened – steadfast in our commitment to do the best we can."
He quoted Dr King to support his argument that "the future of banking will be quite good", with the civil rights leader's quote: "The arc of the moral universe is long, but it bends toward justice."
In an even more unusual reference for a bank chief executive, Mr Dimon, who takes time on his missives to shareholders and has drawn praise from his letter-writing idol Warren Buffett, cited Mr Pinker on human beings' diminishing violence.
"Cruelties such as torture and slavery over many, many years have become increasingly rare (though they tragically still exist)," said Mr Dimon.