 The CBOE Volatility Index, or so-called VIX, and related exchange traded funds have seen some wild swings this year, and volatility traders are hedging against even bigger oscillations ahead. Year-to-date, the iPath Series B SP 500 VIX Short Term Futures ETN NYSEArca: VXX increased 19.6 and the ProShares VIX Short-Term Futures ETF NYSEArca: VIXY advanced . 