The stock market rally lost some of its luster by late afternoon, though equities remained sharply higher to close out the session. Better chances of a 'remain' vote in the 'Brexit' referendum helped to fuel gains. Marathon Oil (MRO - Get Report) rose after agreeing to acquire PayRock Energy from private-equity firm EnCap Investments. The $888 million deal is expected to close in the third quarter. Twitter (TWTR - Get Report) was higher after acquiring Magic Pony Technology, a machine-learning developer that specializes in images. Financial terms were not disclosed but sources say the social network paid roughly $150 million. Hertz (HTZ - Get Report) jumped ahead of its split on Wednesday. Analysts at Morgan Stanley reiterated a BUY rating ahead of the split.