Merck (MRK) has recently been on Zacks.com's list of the most searched stocks. Therefore, you might want to consider some of the key factors that could influence the stock's performance in the near future.Over the past month, shares of this pharmaceutical company have returned -1.6%, compared to the Zacks S&P 500 composite's +2.1% change. During this period, the Zacks Large Cap Pharmaceuticals industry, which Merck falls in, has gained 2.2%. The key question now is: What could be the stock's future directio ...