(CNBC) — U.S. stocks gave up gains as the close neared to end lower Wednesday, after the conclusion of Fed Chair Janet Yellen’s press conference and the Federal Reserve meeting.

The Dow Jones industrial average and S&P 500 posted their first five-day losing streak since the one ending Feb. 11.

“I don’t think this was a good day at all for Fed credibility and it wasn’t a good day at all for them generating confidence for monetary policy,” said Ward McCarthy, chief financial economist at Jefferies. “The impression they create is that monetary policy is just a drift. It’s not clear it’s being driven by the dual mandate and the decision-making is just knee-jerk.

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