President Donald Trump’s chief economic adviser Gary Cohn said he sees a major risk evolving in clearinghouses, platforms that regulators turned to for swaps following the 2008 financial-market crisis.

According to a report on Bloomberg, Cohn said as “we get less transparency, we get less liquid assets in the clearinghouse, it does start to resonate to me to be a new systemic problem in the system,” Cohn, director of the White House’s National Economic Council, said at a banking conference in Washington on Sunday.

Cohn isn’t the first to raise the risk. JPMorgan Chase & Co. and BlackRock Inc. have argued for years that clearinghouses pose their own threats, shifting risk to just a handful of entities. The Treasury Department’s Office of Financial Research has warned that clearinghouses used for derivatives trades can be vulnerable and potentially spread risks through the financial system.