Masimo Corp. (Nasdaq: MASI) shares advanced 9.1 percent to $30.09, on volume of 2.2 million shares, or four times its usual daily average, after the medical-technology firm extended a royalty agreement with Covidien PLC.

Microsoft Corporation (Nasdaq: MSFT) traded in 46.9 million shares, trailing its daily volume of 60.7 million. Prices were flat at $27.66.

Rediff.com India (Nasdaq: REDF) shares fell 11.5 percent to $6.24, on volume of 788,347 shares, falling behind its daily average of 859,473.