#10 Centene
Ticker: CNC
YTD stock performance: 48%
Market cap: $1.8 billion
Fortune 500 Rank: 493

Shares of Centene, which provides managed care programs and related services to individuals under Medicaid, surged as the company continued to add more members and expand into new states, including Florida, Illinois, Mississippi and Texas.

In its last quarterly report, St. Louis-based Centene boasted 1.6 million members, up almost 8% from a year ago. Investors were also pleased that the company raised its outlook for the year.

Centene's stock has also benefited from talk that the managed-care provider could be ripe for a takeover, following a slew of acquisitions by major health insurers of smaller companies that specialize in covering Medicaid patients.

Wells Fargo analysts say the company is also likely to benefit from health reform, since it is set to substantially expand Medicaid eligibility. Cash-strapped states have already started looking into shifting recipients to managed-care providers, which have promised to keep costs low.


By Maureen Farrell and Hibah Yousuf @FortuneMagazine - Last updated December 22 2011: 11:33 AM ET
Join the Conversation
Fortune 500: Worst stocks of 2011

It was a tough year for many major corporations, but this neglected bouquet of Fortune 500 companies stood out for particularly poor performance. From a bankrupt airline to an aging camera maker, here are the biggest losers.

Market indexes are shown in real time, except for the DJIA, which is delayed by two minutes. All times are ET. Disclaimer Morningstar: © 2014 Morningstar, Inc. All Rights Reserved. Disclaimer The Dow Jones IndexesSM are proprietary to and distributed by Dow Jones & Company, Inc. and have been licensed for use. All content of the Dow Jones IndexesSM © 2014 is proprietary to Dow Jones & Company, Inc. Chicago Mercantile Association. The market data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved. FactSet Research Systems Inc. 2014. All rights reserved. Most stock quote data provided by BATS.