Headline flow has been rampant in IBD’s Medical-Services group lately. Catamaran (CTRX) surged 24% on March 30 after UnitedHealth Group (UNH) announced plans to buy the provider of pharmacy benefit management services for $12. 8 billion. In February, Rite Aid (RAD) announced a $2 billion deal to acquire privately held EnvisionRX, another provider of pharmacy benefit management services.