7. Carrizo Oil & Gas ( CRZO), operating through subsidiaries, is engaged in the exploration, development, exploitation, and production of oil and natural gas in the Barnett Shale in North Texas, the Marcellus Shale in Appalachia, the Niobrara Formation in Colorado, the Eagle Ford Shale in South Texas and in proven onshore trends along the Texas and Louisiana Gulf Coast regions. Proved reserves estimated for 2010, grew 40% year-over-year to 842 Bcfe, with 671 Bcfe natural gas. Of the proved reserves, 48% are developed. The Marcellus Shale accounts for about 3 Bcfe of reserves. The company added a second development drilling rig in the Marcellus Shale in northeastern Pennsylvania. The stock is expected to deliver 10% returns in the next one year with analysts' buy ratings of 63%. The stock is trading at 17.6 times its estimated 2011 earnings.