CVSCVS Health Corporation

CVS Health is a pharmacy chain, an insurer and a pharmacy benefit manager rolled into one.

Three parts joined by one chain. Pharmacies dispense medicines and provide basic care. The Aetna insurance arm collects premiums and pays for treatment. Pharmacy benefit management negotiates rebates with manufacturers on behalf of health plans — and that part carries the highest margin.

The point of the structure is that one company controls demand, supply and the intermediation between them. It is also what draws regulatory attention: rebate mechanics are opaque, and the middleman's role in drug pricing is a recurring subject of investigation.

Retail pharmacy is meanwhile under pressure: stores are closing and demand moves online and to discounters. The insurance arm is sensitive to the share of premiums spent on claims, which in programmes for the elderly rose faster than expected. CVS pays a dividend and carries meaningful debt from acquisitions.