The markets opened mixed with the Dow rising 22 points to 16,358 as investors await comments from Federal Reserve Chair Janet Yellen. Nasdaq slipped 5 points to 4327. 

On the upside 

Synthesis Energy Systems (Nasdaq: SYMX) and Zhangjiagang Chemical Machinery received a 20-year business license from China for their joint venture ZCM-SES Sino-U.S. Clean Energy Technologies.

Horizon Pharma (Nasdaq: HZNP) will pay approximately $660 million in cash and stock to acquire Vidara Therapeutics International.

KB Home (NYSE: KBH) swung to a greater than expected profit for the first quarter.

On the downside

Renren (NYSE: RENN) reversed year ago losses to post a profit for the fourth quarter but the Chinese social networking site forecast current quarter revenue below expectations. 

Profit taking weighed down shares of BG Medicine (Nasdaq: BGMD).

Investors locked in profits on Geron (Nasdaq: GERN).

In the broad market, declining issues outpaced advancers by a margin of nearly 10 to 9 on the NYSE and by more than 9 to 7 on Nasdaq. The broader S&P 500 added a point to 1873. Bitcoin eased $4.55 or 0.74% to $610.95.