A falsely reported update on President Trump's tariff policy set the stage Monday for one of the strangest trading sessions in recent memory.

Shortly after the opening bell, the S&P 500 ( ^GSPC ) was down nearly 5%. Within 30 minutes, it was up 3% as confusion emerged over whether President Trump was considering a 90-day pause on his tariff rollout.

As the White House refuted the reports , stocks lost those gains.

"No signal, lots of noise," Citi analyst Stuart Kaiser said in a note to clients following Monday's close. "At the edges, tariff negotiation headlines and a noisy-flat day are incremental positives."

Read more: The latest news and updates on Trump's tariffs

Markets finished the day off their session lows, with the tech-heavy Nasdaq Composite ( ^IXIC ) climbing into the green by late afternoon. The Dow Jones Industrial Average ( ^DJI ) shed around 350 points, while the S&P dropped 0.2%. All three of the major averages had opened the day down more than 3%.

Chris Watling, chief market strategist at Longview Economics, told Yahoo Finance on Friday that the recent sizable intraday moves signal the market "wants to rally."

"Give it a sniff of something that's good news, and whoosh, off you go," he said. "There's a lot of downside protection in this market, a lot of fear ... That is a very, very big move in a very short period of time. So it's indicative of the way the market is positioned."

Headlines that White House economic adviser Kevin Hassett said Trump would consider the pause on tariffs caused the immediate surge in stocks — until it became clear that he didn't actually say that.

"I think the president is going to decide what the president is going to decide," Hassett said in an interview with Fox News when asked specifically if Trump would consider a 90-day pause. Shortly after the comments, stocks sold off once again before paring losses by mid-afternoon.

The White House later described the initial headlines on the pause as "fake news" in a series of posts on X, making clear to investors that the Trump administration is not backing down on implementing reciprocal tariffs on April 9. Trump himself confirmed such a stance while speaking at the White House on Monday.

"Well, we're not looking at [a pause in tariffs]," Trump told reporters after meeting with Israeli Prime Minister Benjamin Netanyahu. "We have many, many countries that are coming to negotiate deals with us, and they're going to be fair deals, and in certain cases, they're going to be paying substantial tariffs."