The broad-based S&P 500 declined 0.1 percent to 2,790.51, and the tech-rich Nasdaq Composite Index also fell 0.1 percent to 7,541.49.
Stocks with big moves included Best Buy, which surged 14.2 percent after reporting better-than-expected fourth-quarter earnings behind a three percent increase in comparable sales and Mylan, which plunged 13.4 percent following a disappointing earnings forecast.
Analysts were looking ahead to a second day of testimony with Federal Reserve Chair Jerome Powell, who again adopted a dovish tone on interest rates on Tuesday.
In another high-profile hearing, US Trade Representative Robert Lighthizer will update lawmakers on the state of US-China trade talks. An even more closely scrutinized hearing will see President Donald Trump's former personal attorney Michael Cohen publicly discuss the polarizing US president's conduct.