After years of stagnant activity, mergers and acquisitions surged in 2014, with the announcement of more than 7,500 deals with a combined value exceeding $3.5tr. That's an increase of more than 7 percent by number and more than 25 percent by value compared with 2013. While that volume hasn't yet reached the high of nearly 10,000 deals set in 2007, a new wave of activity is clearly under way.