U.S. stocks are shaky after President Donald Trump said he had talked about the concept of firing the head of the Federal Reserve.

Federal Reserve Bank of New York President John Williams declined on Wednesday to comment on President Donald Trump’s attacks on the central bank and what it might mean if the president were to somehow remove the Fed’s leader from office.

Trump and White House allies have intensified pressure on Powell, urging the Fed to cut its key interest rate through a multi-front push.

Stocks plummeted when a series of reports indicated president Donald Trump was close to firing the Fed chair. They soared once he denied them.