Stocks were trading mixed Wednesday as investors reacted to earnings news and testimony by Federal Reserve Chair Janet Yellen.

The markets bounced around after the release of Yellen's speech before the Joint Economic Committee as early gains faded and then rebounded again.

The  Dow Jones industrial average was up 0.7% and the Standard & Poor's 500 index gained 0.4%.

But tech stocks suffered once again as shares of  Twitter fell further, dropping more than 3%. The Nasdaq composite index was down 0.5%.

Shares of  Whole Foods plunged nearly 20% in early trading after the company cut its profit outlook late Tuesday.

AOL dropped 20% after the company said net income fell 64%.

U.S. stocks dipped Tuesday as investors registered disappointment with corporate earnings reports, and as Twitter's shares plunged 18% after company insiders were allowed to sell stock for the first time since its IPO.

In Asia, the poor showing on Wall Street in the prior session spilled over into trading overseas as the Nikkei index closed down almost 2.9% to 14,033.45. Hong Kong's Hang Seng index declined 1.1% to 21,746.26.

European bourses were trading mixed. London's FTSE 100 index was down 0.2% and Germany's DAX rose 0.4%.

The price of oil rose after industry data showed a decline in U.S. supplies. Oil rose $1.15 to $100.65 a barrel.

Chinese e-commerce giant Alibaba Tuesday filed its much-anticipated plans to sell shares in what could be one of the biggest initial public offerings ever.

 Contributing: The Associated Press