US STOCKS-Wall St little changed with focus on Yellen; biotechs up
* Dow Chemical to spin off unit, merge it with Olin
* Healthcare buoys indexes as biotechs bounce back
* Fed Chair Janet Yellen to speak shortly before the closing bell
* Indexes: Dow flat, S&P up 0.1 pct, Nasdaq up 0.3 pct (Updates prices, adds GDP data, comment)
By Rodrigo Campos
NEW YORK, March 27 (Reuters) - U.S. stocks edged up on Friday, with major indexes trying to avoid falling every day this week, ahead of a speech by Federal Reserve Chair Janet Yellen that could make for a volatile close on Wall Street.
Healthcare stocks helped buoy indexes with biotech stocks up 1.6 percent following four sessions of losses, while energy weighed the most on the S&P 500 as crude prices resumed their decline.
Fed Chair Yellen will speak on monetary policy in San Francisco, just 15 minutes before the closing bell (1945 GMT), and traders will keep an ear out for clues on the timing of the start of the tightening path at the Fed.
Equities have traded in lock step with the U.S. currency of late ahead of the start of earnings season, as traders gauge how much the greenback's strength will hurt corporations' bottom lines. Continuación...