US STOCKS-Wall St turns lower as Boeing, Biogen weigh
* Indexes turn lower in afternoon trading
* Broadcom and Yahoo rally after results
* Fall in crude oil weighs on energy shares
* Indexes down: Dow 0.4 pct, S&P 0.3 pct, Nasdaq 0.5 pct
By Ryan Vlastelica
NEW YORK, Oct 22 (Reuters) - U.S. stocks turned lower in afternoon trading on Wednesday, with major indexes erasing earlier gains as both Boeing and Biogen sold off following their results.
Indexes had traded in positive territory for much of the session, putting the S&P 500 on track for a fifth straight day of gains. Earnings drove the move higher, with technology and material shares up on the back of strong results.
Biogen Idec was the biggest drag on the S&P 500, falling 7 percent to $303.88 after the company reported sales of its big-selling new multiple sclerosis drug, Tecfidera, that fell short of Wall Street's lofty expectations. It also reported a higher-than-expected quarterly profit and raised its full-year earnings forecast.
Boeing Co lost 3.4 percent to $122.83 despite reporting higher-than-expected earnings and lifting its outlook, as analysts raised concern about the costs of the 787 Dreamliner. Its decline comes after a rise of 5.8 percent over the four previous sessions. Continuación...