Here's Why Eli Lilly Stock Dropped 12% Last Month

News from a competitor gave investors an unwelcome dose of reality.Shares of Eli Lilly (LLY -2.65%) fell 20% in July, according to data from S&P Global Market Intelligence. The pharmaceutical stock tumbled after one of the company's competitors announced promising clinical trial news on an obesity drug. Lilly has two obesity products that are powering sales right now, and it could lose market share ahead of schedule if any of its rivals push smoothly through development.Unwelcome news from a key competitorO ...