Why Kala Pharmaceuticals Stock Sank Today

Why Kala Pharmaceuticals Stock Sank Today

Shares of Kala Pharmaceuticals (NASDAQ: KALA) were sinking 17.4% as of 3:30 p.m. EDT on Tuesday. The big drop came after the drugmaker announced FDA approval of Eysuvis for the short-term treatment of dry eye disease. Aren't biotech stocks supposed to go up when they win FDA approval for a drug?