Gary Cohn has a long Wall Street track record but no experience in the realm of monetary policy.

President Donald Trump is considering appointing Cohn, his chief economic adviser, to take over as chairman of the Federal Reserve when Janet Yellen’s term expires early next year. Cohn’s lack of monetary policy experience and the absence of a public record of his thoughts on monetary policy were the focus of a recent interview on Bloomberg TV with Neal Soss, the vice chairman for fixed income as Credit Suisse Securities.

“Any time you pick someone who’s got a deep academic track record, like a Bernanke, like a Yellen, you have a highly predictable setting for monetary policy,” Soss said. “Gary Cohn doesn’t have that kind of grounding, so from the point of view of Fed watchers there’s at least an initial phase where you have to view that as a less predictable figure and a less predictable policy stance.”

Trump has said he prefers a low-interest rate policy, which many economists view as economically stimulative. But Cohn’s views are unknown. And if he were to be nominated and confirmed as Fed chair, he’d be able to set policy independently from what Trump might like.

This combination of independence plus a lack of a track record could be a cause for concern. Business Insider’s Pedro Nicolaci da Costa recently wrote an article describing a potential Cohn Fed chairmanship as “a looming threat to the stock market’s calm.”

Cohn’s time on Wall Street doesn’t offer much guidance for how he might conduct monetary policy or the related bank supervisory roles the Fed has.

“So what happens when the question arises, just what level of excess reserves does the system want to permit the banks to have and therefore how far should the balance sheet reduction go?” Soss asked.

Cohn would have to rely on the Fed’s staff, Soss said. He just does not come equipped with that kind of deep knowledge of the monetary system.