NEW YORK - US stocks reversed early big losses to close mixed Wednesday, as investors continued to assess impacts of the Chinese central bank's decision to improve its foreign exchange rate formation system.

The Dow Jones Industrial Average edged down 0.33 point, or less than 0.01 percent, to 17,402.51. The S&P 500 added 1.98 points, or 0.10 percent, to 2,086.05. The Nasdaq Composite Index gained 7.60 points, or 0.15 percent, to 5,044.39.

Chinese yuan extended its decline on Wednesday but is unlikely to depreciate significantly as the central bank and stable fundamentals will not allow the currency to go into freefall.

The spot rate fell about three percent to its lowest level since October 2012 when the central bank reformed the exchange rate formation system on Tuesday. The central parity rate fell 1.6 percent, to 6.3306 against the US dollar on Wednesday.

In a latest statement released on Wednesday, the central bank said there was no reason for the yuan to depreciate further.

The IMF described the Chinese central bank's move as "a welcome step" in a statement, saying a more market-oriented exchange rate would facilitate the operation of the special drawing rights (SDR) if the yuan was included in the basket.

In corporate news, shares of Alibaba plunged 5.12 percent to $73.38 apiece Wednesday after the China's e-commerce giant posted the slowest growth in more than three years.

Alibaba's revenue for the quarter ending June 30, 2015 was $3.265 billion, an increase of 28 percent compared with the same quarter of 2014.

Macy's Inc slumped 5.06 percent to $64.11 per share after posting weaker-than-expected quarterly results. It also cut its full-year outlook.

The retailer's earnings were 64 cents per diluted share for the second quarter of 2015, compared with earnings of 80 cents per diluted share in second quarter 2014.

On US economic front, the number of job openings was little changed at 5.2 million on the last business day of June, the Labor Department reported Wednesday.