Markets took a stunning swing Monday morning after an account on X erroneously claimed that President Donald Trump was weighing a 90-day pause on his sweeping tariffs.

The unsubstantiated report added trillions of dollars to the S&P 500 within minutes of the headline. Those gains quickly wiped out after the White House denied the substance of the post. A White House official confirmed to POLITICO that the post was “Fake News.”

The wild swings in the markets Monday indicate how Wall Street investors increasingly are shell shocked by the current economic state while trying to navigate the uncertainty of Trump’s aggressive policy moves.

A user on X posted just after 10:00 a.m. that National Economic Council director Kevin Hassett said Trump was considering a 90-day tariff pause in a Fox News interview from earlier Monday morning. In that interview, Hassett was asked whether the president would consider a pause, after hedge fund billionaire and Trump supporter Bill Ackman said he should take a “90-day time out” on the tariffs, which have wiped out trillions of dollars from the global stock market.

“I think the president is going to decide what the president is going to decide,” Hassett said in response.

The inaccurate post that followed prompted wire services and networks, including CNBC, to air reports that Trump was considering the pause for all countries aside from China. Within minutes of the reported change in policy, the S&P, Dow Jones and tech-heavy Nasdaq all surged, before taking another dramatic fall once administration officials denied the report. At one point today, the S&P 500 surged from a loss of 4.7 percent to a peak gain of 3.4 percent, briefly adding trillions of dollars in market value before plunging again.

Trump has not indicated Monday that he is backing off his tariff threat — set to take effect on Wednesday — writing a series of defiant posts on Truth Social.