By Jon "DRJ" Najarian, co-founder of OptionMonster.Humana ( HUM) is up more than 7% and seeing heavy call activity amid rumors of a takeover by Aetna ( AET). More than 26,500 HUM calls traded in the first hour of the day at various strikes, according to OptionMonster's tracking systems. That's nearly six times the average daily call volume for the health-care provider in 60 minutes. The stock was up as much as 16% to $26.75 by mid-morning but has fallen back to $24.75, still up some 7.3% on the day but less than half of its 52-week high of $51.85. Near-term price targets for Humana are in the range of $32 to $38 per share, but we're hearing some rumors of buyout bids of up to $40. Managed-care companies in general have outpaced the rest of the market in recent days after being hit hard on concerns over regulatory changes under the Obama administration's health-care reform initiatives. Some analysts, however, believe that many of these names have been oversold. The writer has no holdings in the securities mentioned.