Just as there are some niches of financial markets where asset prices soared over the past three months, there are other pockets where prices dropped dramatically.

The worst performing ETFs of the last three months come mainly from three categories: volatility, gold and oil, and their fates are inextricably linked to global economic dynamics. The falling price of oil, the relative decline in volatility in recent months, increasing interest rates and a brief relief rally that may have hampered demand for gold all took tolls on most of the ETFs listed here.

Curiously, though, the two worst performing ETFs during the three months ending Sept. 16 had nothing to do with volatility, oil or gold.              

10. iPath B S&P 500 VIX S/T Futs ETN   VXX   -22.01%

VXX, which tracks an index of S&P500 VIX futures—instruments that reflect the volatility of the S&P 500 index—was a poor performer as volatility experienced a pronounced decline from highs in June. As interest-rate policy continues to spur some equity market volatility, the fortunes of volatility exchange-traded notes may reverse.