Citron Research’s tweet suggesting President-elect Donald Trump begin his war on drug pricing with pharmacy benefit manager Express Scripts caused the company’s stock to fall as much as 9 percent ...

Pharmacy benefit managers, which set how drugs are covered by health insurance, have faced a decade of scrutiny from regulators and lawmakers over pricing.

They're the two biggest pharmacy benefits managers in the world, and they compete against each other every day. While CVS Health boasts a higher market cap thanks to its retail pharmacies, Express ...