Pinto said that the firm's investment banking revenues are forecast to be down 25% in the first quarter.
Markets revenues are down 20% year-on-year, Pinto said, speaking at JPMorgan's Investor Day conference.
Importantly, Pinto noted, the start to 2015 is a tough comparison period for markets revenues, because the division saw an increase in flows during that period after the Swiss National Bank decided to unpeg the franc.
JPMorgan topped league tables in 2015 in terms of global revenue. Elsewhere in the same presentation, the firm said that its market business had outperformed those of its rivals over the past few years.
So when JPMorgan has a tough start to the year, the rest of Wall Street likely will too.
In a recent note, Goldman Sachs analyst Richard Ramsden said that the first quarter could be the weakest in recent history for capital markets revenues across the Street.
He projected capital markets revenues will be down 15% year-on-year for the first quarter.
Ramsden attributed that to a handful of factors, including higher market volatility, wider credit spreads, lower equity valuations, slowing issuance, a tough comparison period, and uncertainty around the trajectory of economic growth across the globe.
A number of other analysts had started forecasting disappointing first quarter revenues in recent weeks. Still, a 20% decline in markets revenues and a 25% decline in investment banking fees is worse than anyone had forecast. It's the scale that's really notable.
Morgan Stanley's global head of sales and trading, Ted Pick, gave a similar warning about the rough start to the year for Wall Street traders earlier this month.
"The question is going to be, with the animal spirits having sort of disappeared here and the classic risk taking mode, whether we're going to continue to see this gapping around, which I think will look more like recent sequential quarters than it would like the healthy first quarter we saw last year," he said, speaking at the Credit Suisse financial-services forum.
As Business Insider's Matt Turner pointed out, that comment is critical. The first quarter is typically the most important period of the year for trading desks, as asset managers move into new positions.
If that isn't happening, and the first quarter looks just like the third or fourth quarter, for example, then trading revenues are likely to come in down on the first quarter of last year.