The Dow Jones industrial average fell about 70 points, with Nike contributing the most losses. Nike's stock declined 6 percent on the back of mixed quarterly results.
The S&P 500 fell 0.16 percent, with financials and telecommunications leading decliners. Financials, the best-performing sector since the U.S. election, suffered their worst day since Brexit in the previous session.
The Nasdaq composite held around breakeven.
Stocks suffered their worst day of the year Tuesday — in part — because of fears that a prolonged battle in Congress to repeal and replace Obamacare could delay tax reform, deregulation and government spending. Read more at CNBC