WASHINGTON — President Donald Trump’s social media posts ahead of his announcement Wednesday that he was reversing course on many tariffs have fueled suggestions by several Congress members of potential market manipulation.

At 9:33 a.m. Wednesday, the president told his followers on Truth Social, “BE COOL! Everything is going to work out well. The USA will be bigger and better than ever before!” Several minutes later, he added, “THIS IS A GREAT TIME TO BUY!!! DJT.”

Trump then announced at 1:18 p.m. that he was suspending many tariffs, saying that there would be a 90-day pause for countries that have not retaliated against the U.S. A 10% baseline tariff will remain in effect, and notably, China was excluded from the reprieve. On Thursday, the Trump administration clarified that Chinese goods exported to the U.S. would be tariffed at 145%.

U.S. trading markets spiked to one of their biggest gains since World War II following the president’s announcement — with the S&P 500 climbing 9.5%, the Dow Jones Industrial Average increasing nearly 3,000 points and the Nasdaq composite jumping 12.2%.

As stocks surged, Democratic lawmakers began questioning who knew about the pause of tariffs beforehand and if anyone had profited from the suspension. 

Sen. Adam Schiff called for an investigation into whether the president, his family or other members of the administration “engaged in insider trading or other illegal financial transactions.” Schiff posted the letter that he and Sen. Ruben Gallego, D-Ariz., sent to the U.S. Office of Government Ethics and the White House chief of staff on X. 

“Sadly, you can't foreclose that possibility that people in the administration were cashing in, even as Americans have been losing their retirement savings,” Schiff told Spectrum News on Thursday. “It's a real concern that there's insider trading going on and stock manipulation going on, and people are enriching themselves at the expense of the public.”

Schiff said White House officials and Cabinet members have not been filing mandated reports on their stock trades and that Democrats "want to find out why. And I'm confident we will... and we're going to share with the American people whether there's insider trading going on."

"People outside the administration go to jail for doing that. There are federal laws that prohibit this, and we want to make sure that they're enforced,” he added.

Speaking to Spectrum News on Wednesday evening, Rep. Alexandria Ocasio-Cortez, D-N.Y., said, “I don’t think that it was a coincidence. I don’t think that Trump just coincidentally said buy stocks and then shortly later made an announcement that dramatically inflated and dramatically raised these asset prices.” 

Sen. Chris Murphy, D-Conn., in a post on X said, “The bottom line is that the chaotic nature of this tariff policy with Trump's position changing every single hour gives ample opportunity for any individual who has early access to information about the White House’s change in position to make boatloads of money.”

Rep. Mike Levin, D-Calif., also told Spectrum News on Thursday that "I certainly believe that, market manipulation is a real possibility here," but that the Justice Department lead by loyalists to the president and a Republican-controlled Congress are failing to provide a check on the administration. He's called on all members of Congress to share their stock trades in the last week and reiterated his call for a stock trading ban for members of Congress.

"I want to know who knew about the decision was going to make. We know [Commerce Secretary] Howard Lutnick was in the room, for example. Who else knew about the pause decision? When did they know it?" Levin said.

"I certainly believe that, market manipulation is a real possibility here."@RepMikeLevin tells me "the President of the United States, the Speaker of the House, we as public officials, all of us in Congress, should not be giving stock tips."

Says he wants to know who knew… pic.twitter.com/J5vco7FCXt

— Cassie Semyon (@casssemyon) April 10, 2025

Rep. Steven Horsford, D-Nev., raised his own concerns with U.S. Trade Representative Jamieson Greer, who had been testifying at the House Ways and Means Subcommittee on Trade when the president announced the tariff pause.

“Is this market manipulation?” Horsford asked Greer. “If it was a plan, if it was always the plan, how is this not market manipulation?”

“It’s not market manipulation,” Greer responded. “We are trying to reset the global trade system.”

In response to an inquiry about the posts, White House spokesman Kush Desai wrote, "It is the responsibility of the President of the United States to reassure the markets and Americans about their economic security in the face of nonstop media fearmongering. Democrats railed against China’s cheating for decades, and now they’re playing partisan games instead of celebrating President Trump’s decisive action yesterday to finally corner China.”

Trump was also asked about his decision to suspend some tariffs at an unrelated event in the White House driveway Wednesday afternoon. "I thought that people were jumping a little bit out of line. They were getting yippy, you know? They were getting a little bit yippy, a little bit afraid," he said.

Later in the afternoon, the president said that he had been mulling the decision for several days, and added that the changes to tariffs "came together early this morning." 

In an email, a spokesperson for the Securities and Exchange Commission declined to comment about posts made by the president Wednesday morning. 

Spectrum News' Kevin Frey and the Associated Press contributed to this report.