Less than two hours before the White House announced new sanctions against Russia, the Dow Jones Industrial Average, S&P 500 and Nasdaq Composite indexes dropped suddenly, only to close below their market open values. Above, the New York Stock Exchange building was photographed, May 6, 2010. Reuters

Major U.S. stock market indexes shot abruptly downward less than two hours ahead of President Barack Obama’s Thursday announcement the U.S. would extend sanctions against Russia for the nation’s alleged “cyberoperations aimed at the U.S. election.”

Around noon Wednesday, the Dow Jones Industrial Average (DJI) dropped nearly 43 points, or 0.22 percent, the S&P 500 (GSPC) fell 5 points, or just over 0.22 percent, and the Nasdaq Composite Index (IXIC) plunged more than 13 points, or about a quarter of a percentage point. While the three indexes rebounded somewhat by market close, the Dow closed 0.07 percent lower than its opening value, the S&P closed 0.03 percent lower than its market open and the Nasdaq Composite fell 0.12 percent over the course of the day.

As UBS Financial Services Floor Operations Director Art Cashin told CNBC Thursday after the dip, the market likely overreacted to the White House decision. The sanctions, while predominantly involving Russian intelligence groups and cyberoperations companies, hardly touch trade relations with America’s 25th-largest trading partner, with which import and export activity has generally declined since 2011.

“All we know is they expelled 35 diplomats,” Cashin said. “You’ve got to see more sanctions, you’ve [got] to see trade restrictions. Otherwise it’s not going to affect the market.”

Cashin also suggested that the market comeback, however mild it might have been, could be tied to expectations for friendlier U.S.-Russia relations following President-elect Donald Trump’s Jan. 20 inauguration.

In addition to nominating Exxon Mobil Corp. CEO Rex Tillerson, a fierce opponent of U.S. sanctions against Russia, as his secretary of state, Trump has long raised eyebrows over his ties to Moscow as well as his personal stance on the Russian government and its president, Vladimir Putin.

Investors, Cashin continued, assume when Trump enters office, “he may make things calmer.”