Humana shares soared well beyond all-time high prices Friday afternoon on speculation that the company, one of the nation's biggest health insurers, might be up for sale.

Analysts have been discussing for a few weeks the possibility that large health insurers flush with cash may be hunting for a big acquisition. Deal-friendly low interest rates and expectations for another wave of consolidation also are fueling the speculation.

The Wall Street Journal reported Friday that Humana is considering a sale and has received takeover interest.

A Humana spokesman did not return calls from The Associated Press seeking comment.

Louisville, Ky.-based Humana is seen as an attractive target in part because it is the second-largest provider of Medicare Advantage plans, a key source of future growth for insurers. Enrollment has already grown briskly the past several years for these privately run, federally funded versions of the Medicare program for people over age 65 and the disabled.

That's expected to continue as baby boomers become eligible for the coverage and as more companies drop retiree health benefits. The health care overhaul has chopped funding for these plans, but the worst of that has passed, and analysts see much less uncertainty in the future for the coverage.

In addition, insurers are gaining a better understanding of the health care overhaul, the massive federal law that has helped provide coverage for millions. They are learning that scale matters in terms of gaining negotiating leverage for rates over care providers.

"There's got to be another wave of consolidation that occurs, and our view is that Humana would either be the first to go or be one of the first to actually make an acquisition themselves," said Thomas Carroll, who covers the industry for the investment bank Stifel.

Leerink analyst Ana Gupte said Humana makes an attractive target in a sector "ripe for consolidation."

"We think (Humana's) Medicare Advantage business and capability makes it especially attractive to some of the largest insurers," she wrote in a note to investors.

Aside from Medicare Advantage plans, Humana Inc. also offers commercial coverage as well as insurance for military members and their families.

The company's stock rose as high as $219.79 during afternoon trading, blowing past its previous all-time high price of $183.05 in Friday afternoon trading. The shares finished with a gain of $36.24, or 20.3 percent, to $214.65. Shares of other major insurers like Cigna Corp., Aetna Inc. and Anthem Inc. also climbed while broader indexes slipped.

Managed care stocks have outpaced the market for a few years now, and the shares of several insurers have reached record high prices. Investors have been drawn by strong performances, fattened dividends and dwindling uncertainty about the overhaul's impact on the sector.