Stocks Closing Mixed After Fed Chief's Warning

(New York, NY) -- Stocks are closing mixed after a warning from the Fed chief on the valuations of social media and biotech stocks. The Dow Jones Industrial Average gained six points to close at 17-061 but the Nasdaq dropped 24 points to 44-16. The S&P 500 shed four points to end the session at 19-73. Fed chief Janet Yellen told a Senate panel today "equity valuations of smaller firms as well as social media and biotechnology firms appear to be stretched." Shares in Facebook dropped over one percent.