Investors often view Pharmaceutical stocks as safe havens during periods of market turbulence. Stock market volatility or even economic downturns usually don't affect drugmakers' underlying businesses much, if at all. Physicians prescribe medications, and patients take them, regardless of the S&P 500's gyrations or how macroeconomic factors might shift.Indeed, shares of the three biggest pharmaceutical companies based on market cap -- AbbVie (ABBV 2.64%), Eli Lilly (LLY 3.78%), and Johnson & Johnson (JNJ 1. ...