When investment banks record a painful quarter, it’s not uncommon to hear the same word crop up all across Wall Street: “backlog.” Following spells of market turbulence — like the turmoil seen in the first few months of 2016 — banks often assure investors that a slate of corporate deals will soon be padding profit margins.

A new report from Fitch Ratings sounds a warning on that guidance.

Looking back five years, the ratings agency found that pronouncements of investment banking backlogs didn’t necessarily correlate with higher future profits from those divisions. Instead, dealmaking revenue is yoked largely to overall market volatility.

It’s no surprise that the more unstable markets become, the less likely it is for banks to roll out initial public offerings, mergers, acquisitions and other corporate deals — an increasingly important source of profits for big financial institutions.

What's more notable, however, is how weak the relationship is between backlog announcements and actual investment banking revenue.

Compare that with the relationship between the Chicago Board Options Exchange Volatility Index, which rises when fear mounts on Wall Street, and investment bank revenue. When the VIX, as it is better known, falls, investment bank earnings rise, and vice versa.

“The implication for revenues of bank announcements of large [investment banking] backlogs should be viewed as contingent on relative market stability,” Fitch wrote. In other words, investors shouldn't trust a bank’s promise of a backlog any more than they can predict market volatility.

This year should prove a test case for Fitch’s warning. After a highly volatile first two months of the year, four of the five largest investment banks pointed investors to their sizable deal backlogs. Citigroup was one of them.

“Investment banking revenues should recover from first-quarter levels if the environment is favorable, based on the significant backlog of deals we have pending with our clients,” Citigroup Chief Financial Officer John Gerspach told investors after the bank recorded a 27 percent earnings slide in the first quarter.

But whether that backlog turns into profits in coming quarters, Fitch said, depends more on the broader market environment than on Citigroup’s own dealmaking prowess.