 The CBOE Volatility Index and VIX-related exchange traded funds surged on Tuesday as U.S. equities retreated in the face of bond yields hitting a two-year high. Among the best-performing non-leveraged ETFs of Friday, the iPath Series B SP 500 VIX Short Term Futures ETN NYSEArca: VXX increased 6.5 and the ProShares VIX Short-Term Futures ETF NYSEArca: . 