2 Reasons to Sell Merck Stock and 1 Reason to Buy

There is plenty to like about Merck (MRK -0.30%). It is one of the largest pharmaceutical companies and the owner of the world's current best-selling drug, cancer medicine Keytruda. Merck generates consistent revenue and profits, has a deep pipeline, and pays a regular dividend.These are all good things, none of which has stopped the company's shares from significantly underperforming broader equities this year. Merck's shares are down by 8% year to date. What's going on with the healthcare giant?Let's cons ...