Best and worst performing ETFs this year By: CNBC.com News December 29, 2014 at 10:13 AM EST Exchange-traded funds tied to biotech and mainland China soared, while commodity and Russia ETFs took a beating. Read More >> Related Stocks: Cohen & Steers REIT Ishares ETF Goldman Sachs Group Intercontinental Exchange Nasdaq Biotechnology Ishares ETF PowerShares DB Agriculture Fund PowerShares DB Oil Fund Real Estate Vanguard ETF S&P Biotech SPDR S&P Oil & Gas Expl & Prod SPDR