Two months back I wrote that shares of Express Scripts (ESRX), a leading pharmacy benefits manager, were bloated at $93 each. A P/E of 30 for the company was simply unsustainable. Today ESRX is down nearly $10 to $74 per share after issuing an in-line earnings report. Although I would not do a complete 180 and go long quite yet, I do think it is time for ESRX shorts to be covered for a 20% gain. Where should the money go? I’m interested in taking a look at Aetna (AET), which is down more than 20% today to $36 per share.