Aetna President Mark Bertolini
Aetna shares are up by nearly 12 percent so far on stronger-then-expected revenues for the fourth quarter. Reuters

Aetna Inc. (NYSE: AET) is up sharply in mid-morning trading on a strong earnings announcement for the fourth quarter.

Shares of Aetna are up 11.93 percent as it announced that it garnered $8.54 billion in revenue in the fourth quarter, or $0.64 per share, beating analysts’ estimates of $8.4 billion, or $0.63 per share.

The uptick is happening on a day when the Dow Jones Industrial Average and the S&P 500 are both down slightly so far by 0.02 percent each, despite jobs data this morning reporting that the unemployment rate is down to 9 percent in the U.S.