Donald Trump sent the US stock market plummeting again, this time with social media snark and derisive playground nicknames aimed at the Chair of the US Federal Reserve. The president, under increasing pressure for singlehandedly destabilizing global markets with his trade war, has turned his attention to interest rates in a bid to avoid what economists increasingly fear is a recession dead ahead. Trump’s public mulling over whether he can legally fire Powell has market watchers eyeing a potential broad-based loss of confidence in the US economy if he were to try it.

The 78-year-old Republican’s taunts came before he met with executives of major retailers at the White House—those whose businesses are set to bear the brunt of tariffs the White House has temporarily suspended. The Monday meeting was said to have included representatives from Walmart, Home Depot, Lowe’s and Target.