BlackRock Healthcare ( MAHCX), a $336 million fund, is up 15.5% this year and 7.8% in the past three months. WebMD Health ( WBMD) is the largest holding at 6% of the fund. It is down 10% this year. The company runs specialized Web sites that provide health information to consumers and health-care professionals, and it develops and runs private Web sites for health-care providers. Warner Chilcott ( WCRX), the second-largest fund holding at 6%, is up 5.7% this year. The company develops specialty pharmaceuticals, including for gastroenterology, dermatology and urology products. Its 2009 acquisition of Procter & Gamble's ( PG) pharmaceutical unit boosted its drug-making potential. The top performer in the top 25 holdings is health-insurance giant Aetna ( AET), up 45.6% this year.