A lack of liquidity in corporate-bond markets could pose a “systemic risk” to the economy when interest rates rise, U.S. Securities and Exchange Commission member Daniel Gallagher said.

Gallagher, a Republican, warned that the Financial Stability Oversight Council, a group of U.S. regulators that monitors emerging systemic risks, hasn’t paid enough attention to the $7.3 trillion corporate-bond market, which has ballooned over the past seven years amid low interest rates. He made the remarks Monday at a banking conference in Washington.

The SEC last year began testing whether fixed-income mutual funds could withstand a possible sell-off during a period of financial stress, people with knowledge of the matter have said. The agency hasn’t made its findings public, but some large money managers have warned the market is primed for failure when the Federal Reserve starts raising interest rates.

Fed Vice Chairman Stanley Fischer said Feb. 27 that the central bank was most likely to raise interest rates in June or September.

Speaking to reporters after his speech, Gallagher said that the SEC’s staff doesn’t appear to be heeding his warnings by planning new rules or other initiatives. He said he would prefer to see money managers and other investors propose solutions but added that the SEC has a role to play.

“It would be a lot better if the SEC could take some action to help the market structure, to create liquidity before we actually have a mess on our hands,” he said.