Health Care Winners & Losers: Coventry

Total enrollment stood at 10.4 million as of Dec. 10, an increase of 165,000 people. But the analyst noted that enrollment increases may not be a good thing for insurers who failed to solve last year's pricing problems.

Overall Wednesday, the Dow Jones Industrial Average fell 3% in afternoon trading. Several insurance companies outpaced that decline with share price drops of between 4% and 5%.

The list included WellPoint (WLP Quote), which fell $1.93 to $36.88; UnitedHealth Group (UNH Quote) off $1.28 to $24.08 and Aetna (AET Quote) off 82 cents to $26.11.

Carroll said the overall market performance, coupled with the release of sour retail data, may have impacted the managed-care sector.