(CNBC) U.S. equities closed lower Thursday, with health care falling approximately 1 percent, a day ahead of a key speech from Federal Reserve Chair Janet Yellen.
The Dow Jones industrial average closed about 30 points lower, with UnitedHealth Group contributing the most losses. The S&P 500 fell about 0.1 percent, with health care lagging. The sector had posted its worst day since June 24 on Wednesday.
"If we look back to last year, it looks like history is repeating itself," said Mike Bailey, director of research at FBB Capital Partners. "I think investors need to be cautious on health care."
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