SMOG was created on 2007-05-03 by VanEck. The fund's investment portfolio concentrates primarily on theme equity. The ETF currently has 146.17m in AUM and 59 holdings. SMOG tracks a market-cap-weighted index of companies that focuses specifically on renewable energy. Such companies are defined as deriving at least 50% of their revenues from wind, solar, geothermal, hydro, hydrogen, waste, and biofuels.