Wall Street stocks suffered another battering Thursday, giving back a sizeable portion of the prior session's gains as investors grappled with lingering uncertainty about President Donald Trump's trade and economic policies.

Major US indices spent the entire day in the red, disappointing traders who had been hoping to extend Wednesday's rally following Trump's pivot on tariffs.

The broad-based S&P 500 finished down 3.5 percent at 5,268.05. The index had soared 9.5 percent on Wednesday.

The Dow Jones Industrial Average dropped 2.5 percent to 39,593.66, while the tech-rich Nasdaq Composite Index slumped 4.3 percent to 16,387.31.

Wednesday's historic rally followed Trump's decision to pause for 90 days many of his most onerous tariffs on trading partners, while doubling down on levies on China.

US stocks wiped out trillions of dollars in value in the sessions after President Trump's "Liberation Day" tariff announcement before the president's reversal on Wednesday.

But by Thursday, investors realized that Trump's tariff pause "is not enough to get people back in this market," said Peter Tuchman, senior floor trader at TradeMas Securities.  

"It's still no clarity," Tuchman said. "We're still in the midst of a major trade war with China, and so where do we go from here?"

Data showed that US consumer inflation contracted 0.1 percent from a month earlier in a reading that was lower than analyst expectations.

But traders have been unnerved by the massive reversals in Trump's policies, resulting in uncertainty that economists warn can paralyze consumers and businesses.

"There's still a lot of apprehension," said Tom Cahill of Ventura Wealth Management, noting that there was uncertainty about whether Trump's tariffs would be back after 90 days.

"Things can change in just a matter of hours with something as simple as a tweet," Cahill said. "Uncertainty is always present when you're an investor ... but the uncertainty level is nearly unprecedented for my 30-year career."

Energy was the biggest loser among the 11 S&P 500 sectors, where 10 groups finished in the red. Only consumer staples mustered a small gain.