UnitedHealth (NYSE:UNH) advanced 3.5% to $112.93 after posting fourth-quarter earnings per share of $1.40 and revenue of $43.6bn.
Amarantus BioScience Holdings (OTCMKTS:AMBS) fell 25% to $0.276, reversing an earlier gain. The biotechnology company entered into a letter of intent with Avant Diagnostics (OTCBB:AVDX), a medical diagnostic technology company, to merge an Amarantus wholly-owned unit, Amarantus Diagnostics, into Avant Diagnostics. Shares of Avant rose 195 to $0.25.
Payment Data Systems (NASDAQ:PYDS) slid 1% to $2.08, erasing an earlier gain. The integrated payment solutions provider announced record transaction processing results for the fourth quarter and year ended December 31, 2015.