The markets opened higher with the Dow gaining 55 points to 24,317 as crude oil prices rose. Nasdaq climbed 32 points to 7241.

On the upside

Gramercy Property Trust (NYSE: GPT) will be acquired by Blackstone Group (NYSE: BX) for a premium of approximately $7.6 billion in cash.

Elliott Management offered to buy Athenahealth (Nasdaq: ATHN) for a premium of approximately $7 billion in cash.

Rising crude oil prices lifted shares of Laredo Petroleum (NYSE: LPI).

On the downside

First quarter earnings for Tower Semiconductor (Nasdaq: TSEM) fell short of expectations.

Cognizant Technology Solutions (Nasdaq: CTSH) reported lower first quarter earnings and cut its full year forecast.

Retreating gold prices weighed down shares of Sibanye Gold (NYSE: SBGL).

In the broad market, advancing issues outpaced decliners by a margin of nearly 7 to 3 on the NYSE and by more than 5 to 3 on Nasdaq. The broader S&P 500 rose 6 points to 2,669. Bitcoin plummeted $238 to $9,264.