There are few more artful communicators on Wall Street than Jamie Dimon. Unlike many of his counterparts, the native New Yorker is willing to speak his mind and can express himself clearly, dipping so easily into the vernacular that he sometimes sounds more like the host of a sports-radio talk show than the boss of the biggest US bank by assets.

But some subjects are a little too complicated for even the JPMorgan Chase chief executive to turn to his advantage. Like other pillars of the banking establishment these days, he is making fateful decisions about how to respond to a new generation of fintech competitors — and explaining his technology spending to outsiders is proving tricky.

Dimon’s difficulties were on display a few days ago when JPMorgan reported its fourth-quarter results. As usual, it made loads of money — a record $48.3bn last year. The bank also made clear that it was not standing still. It said it would increase investments in technology, marketing, new businesses and additional staff by 30 per cent this year to $15bn. Tech outlays of all kinds are expected to total $12bn.