One of the reasons investors look to Big Pharma stocks is their ability to handle the setbacks that their smaller competitors can't. But even Merck (NYSE:MRK), whose roster of blockbuster drugs numbered 11 last year, can only handle so many setbacks. And there's been no shortage of them for the Dow component lately, pressuring shares over the past three months while the Dow Jones Industrial Average and its blue-chip pharmaceutical peers have risen around 10%.

However, positive news emerged today to break Merck out of this holding pattern. Are the gains setting investors up for more disappointment? In the following video, Brenton Flynn outlines the news behind today's move and some historical context that explains the reaction.