1) Express Scripts is the largest pharmacy benefit manager (PBM) in the US but faces slowing growth as its core business reaches maturity. It lacks a compelling valuation and trades around its estimated fair value.
2) Intensifying competition in the pharmaceutical industry may lead to price wars that threaten Express Scripts' business model of aggressively negotiating lower drug prices.
3) Given Express Scripts' maturing business and risks to future growth, investors have an opportunity to realize gains by selling their shares in the company.