Roy Behren and Mike Shannon, professional merger arbitrage investors, make money by placing on bets on how likely it is that a deal will get completed. They do this by investing in targeted companies and sometimes shorting potential acquirers. What's unusual about them is they also give retail investors a way to profit from their decisions through the Merger Fund, a publicly traded mutual fund they run through Westchester Capital Management. Plus, Behren and Shannon give Deal of the Week host Alex Sherman opinions how to reap gains from Yahoo's sale process, the merger of Dupont and Dow Chemical's and Bayer's pursuit of Monsanto.