T. Boone Pickens's portfolio is focused squarely in the energy sector. As of Dec. 31, 2010, funds at Pickens' firm BP Capital Management were valued at right at $276 million. He had 23 positions at the end of the year, including integrated oil companies, gas drillers and a variety of oil and energy-service providers. That was down from a total of 29 in the third quarter. Moves: Pickens eliminated 11 positions and added five during the final quarter of the year. Leaving the portfolio were: Anadarko (APC), Apache (APA), Baker Hughes (BHI), Chevron (CVX), Encana (ECA), Fluor (FLR), Hess (HES), Massey Energy (MEE), Quicksilver Resources (KWK), Schlumberger (SLB) and Southwestern Energy (SWN). New positions were: A123 Systems (AONE), Dynegy (DYN), EOG Resources (EOG), Gastar Exploration (GST) and National Oilwell Varco (NOV). Pickens decreased his holdings in Devon Energy (DVN), Suncor (SU) and Clayton Williams (CWEI), while adding to his stakes in BP (BP), Chesapeake Energy (CHK), Halliburton (HAL), Plains Exploration (PXP) and QEP Resources (QEP). Here are Pickens's largest holdings as of Dec. 31, 2010: • Chesapeake Energy (CHK) • BP (BP) • McMoRan Exploration (MMR) • Weatherford International (WFT) • Plains Exploration (PXP) • QEP Resources (QEP) • EOG Resources (EOG) • SandRidge Energy (SD) • Suncor (SU) • Noble (NE) *See the full SEC filing for T. Boone Pickens' portfolio.