Investors can expect a lower start to the stock market today, as the Dow Jones Industrial Average (^DJI 0.34%) has lost 26 points in pre-market trading. Still, with the index just 46 points below its all-time high it wouldn't take much of an upswing for the Dow to crack back into record territory in the session. Splashy merger and acquisition deals and corporate earnings results look set to drive today's action, as pharmaceutical giant Merck (MRK 0.24%) inked a $14 billion sale and pay-TV king Discovery Communications (DISC.A) logged a massive sales spike for its first quarter.

Market movers

Merck announced this morning that it is selling its consumer care business, including blockbuster brands such as Afrin, Claritin, and Coppertone, to Bayer. The deal is valued at $14.2 billion, but should net Merck about $8 billion after taxes. Merck said it plans to direct that cash first toward new promising investments such as development of its MK-3475 skin cancer treatment, but the windfall should also set the stage for even more capital returns to shareholders. The Dow's top-performing stock so far this year, Merck spent roughly $8 billion on repurchasing its own shares over just the last 12 months. Today's deal makes it likely that those cash returns will continue at a solid clip. The stock was up 1.3% in pre-market trading.

Discovery Communications stock was up 8% in pre-market trading after the company announced strong first-quarter earnings results. Sales for the TV giant, which owns over 200 networks including Discovery Channel, TLC, and Animal Planet, spiked higher by 22% to $1.4 billion as earnings grew 19% to $0.75 a share. That revenue jump was mostly due to a 2013 acquisition that helped Discovery's international business log a 51% sales boost. Still, even without that purchase Discovery's numbers looked great: adjusted sales were up 8% in the quarter. CEO David Zaslav said in a press release accompanying the earnings results that Discovery is well positioned to "capitalize on the growing demand for pay-TV programming worldwide." That rising demand should help power sales of $6.6 billion for the full year and net income of $1.25 billion, according to Discovery's updated forecast, representing respective gains of 20% and 16% over last year.