U.S. stocks fell on Thursday as the market digested Corporate America’s rebellion against President Trump.

The Dow Jones Industrial Average broke a four-day winning streak to fall 274 points or 1.24 percent, the biggest one-day decline since May. Cisco Systems was the worst performing stock on the index. Goldman Sachs fell 1.86 percent.

Many of the companies whose CEOs resigned from the White House’s advisory councils saw significant declines. Shares of J.P. Morgan Chase fell 1.56 percent. Walmart shares were off by 1.58%. 3M shares sunk 1.24 percent. Shares of Under Armour fell 2.04 percent. Shares of Merck, whose CEO was the first to leave the White House panel in the aftermath of the violence in Charlottesville, Va., fell 1.37 percent.

Stocks also seemed to react to a rumor that Gary Cohn, the longtime Wall Street titan who now advises the president on economic policy, might resign. Cohn is leading the White House’s tax reform efforts. Many on Wall Street fear that if he resigned or was forced out of the White House, tax reform would lose steam.

The White House responded that Cohn has no plans to resign. The market’s reaction to the rumor, however, could dim the chances that Cohn could be elevated to head the Federal Reserve. If he is so critical to the White House that his resignation would shake the stock market, President Trump may not want to lose him to the central bank.

The broader S&P 500 index fell by 1.5 percent. The tech heavy Nasdaq composite fell 1.9 percent. Amazon, a frequent target of Trump’s tweets, saw its shares fall by 1.8 percent.