Wall Street opens lower after three-day rally

After three days of gains, Wall Street was lower at the start of trading Friday as investors digested hawkish comments from top Federal Reserve officials as well as uncertainty over the war in Ukraine.

Karl Haeling of LBBW said the "driving force" behind the losses was uncertainty over the global economic impacts of Russia's invasion of its neighbor, which has caused Western nations to impose aggressive sanctions on Moscow and prices of commodities like oil to spike.

Traders also were focused on comments from Fed Governor Christopher Waller and St. Louis Fed President James Bullard, who advocated for more aggressive action from the central bank to contain inflation than the quarter-point rate increase agreed to on Wednesday.

About 10 minutes into trading, the benchmark Dow Jones Industrial Index was 0.5 percent lower at 34,327.25.

The broad-based S&P 500 had lost 0.3 percent to 4,400.15, and the tech-rich Nasdaq Composite Index was 0.3 percent lower at 13,578.31.

Traders are looking ahead to next week, when Fed Chair Jerome Powell will make multiple appearances and could further detail his views on how the central bank should respond to the wave of price increases that has pushed US inflation to a four-decade high.