Donald Trump's election win and his pick for attorney general could be a big boost to Bayer AG's $66 billion purchase of Monsanto Co. that is currently undergoing state and federal antitrust investigations.

Investopedia reports that Monsanto stocks have risen more than 4 percent since Trump's surprise victory. Additionally, Terry Haines of the investment banking advisory firm Evercore ISI said that the president-elect's nominee for attorney general—Sen. Jeff Sessions, a pro-business conservative from Alabama—is good news for any pending mega-deals.

"Sessions' likely nomination and confirmation by the Senate, in which he has served since 1997, is a market positive for merger and acquisition activity," Haines, who heads Evercore's Political Analysis team, wrote in a note last week.

"Sessions as attorney general would shift immediately from the current mostly 'red light' Obama antitrust/competition policy and move towards one that would be friendlier to M&A activity," Haines added.

A successful merger between the German pharmaceutical company and the St. Louis-based agritech giant will form the largest seed and pesticide company in the world. Critics are concerned that the consolidation of the two multinational juggernauts will increase pesticide and herbicide prices for farmers, and will have less incentive to compete and introduce better and cheaper products.

"Farmers get paid less for their crops, more pesticides are used and there are fewer options for consumers at the grocery store," Wenonah Hauter, the executive director of Food & Water Watch, told EcoWatch after Bayer and Monsanto announced acquisition plans in September.