Jon "DRJ" Najarian, co-founder of OptionMonster.

Cigna ( CI) options and those for the entire health care sector have been violently active for weeks, and today is no different.

Cigna's average daily volume is 6,770 options, but more than 20,000 contracts changed hands this morning in the first hour of trading alone, according to OptionMonster's real-time tracking systems. The May upside calls dominated the activity.

More than 10,000 of the calls traded at the May 25 strike, going for 70 cents. These calls are almost a full $4 out of the money as the stock trades around $21, but they would certainly react with any surge. The shares are up on the day, but only by about 2%.

If you liked this article you might like

Healthcare Management Stocks Look Too Pricey for Activists

The Stock That Crashed 25% Overnight Has a Lesson to Teach Us: Market Recon