EVX's index is comprised of 22 companies focused on various environmental services. The fund's top four positions, Waste Management ( WM), Veolia ( VE), Republic Services ( RSG), and Stericycle ( SRCL) command 40% of the fund's portfolio. Compared to a similar mutual fund, the Fidelity Select Environmental Fund ( FSLEX), EVX has outperformed over the past year, though they're running neck and neck year to date. EVX trades about 5,000 shares per day. -- Written by Don Dion in Williamstown, Mass.