Identifying VXX/SVXY Tendencies

Are there reliable predictors supporting strategies for timing exchange-traded notes (ETN) constructed from near-term S&P 500 Volatility Index (VIX) futures, such as iPath S&P 500 VIX Short-Term Futures ETN (VXX) and ProShares Short VIX Short-Term Futures ETF (SVXY), available since 1/30/09 and 10/4/11, respectively. The managers of these securities buy and sell VIX futures daily to maintain a constant maturity of one month, continually rolling partial positions from nearest to next nearest contracts. VXX and SVXY target 1X and -0.5X daily performance relative to the S&P 500 VIX Short-Term Futures Index, respectively. We consider five potential predictors for these ETNs:

1. Level of VIX, in case a high (low) level indicates a future decrease (increase) in VIX that might affect VXX and SVXY.
2. Change in VIX (VIX “return”), in case there is some predictable reversion or momentum for VIX that might affect VXX and SVXY.
3. Implied volatility of VIX (VVIX), in case uncertainty in the expected level of VIX might affect VXX and SVXY.
4. Term structure of VIX futures (roll return) underlying VXX and SVXY, as measured by the percentage difference in settlement price between the nearest and next nearest VIX futures, indicating a price headwind or tailwind for a fund manager continually rolling from one to the other. VIX roll return is usually negative (contango), but occasionally positive (backwardation).
5. Volatility Risk Premium (VRP), estimated as the difference between VIX and the annualized standard deviation of daily S&P 500 Index returns over the past 21 trading days (multiplying by the square root of 250 to annualize), in case this difference between expectations and recent experience indicates the direction of future change in VIX. VRP is usually positive, but occasionally negative.

We measure predictive power of each in two ways: (1) correlations between daily VXX and SVXY returns over the next 21 trading days to daily predictor values; and, (2) average next-day SVXY returns by ranked tenth (decile) of daily predictor values. Using daily levels of VIX and VVIX, settlement prices for VIX futures contracts, level of the S&P 500 Index and split-adjusted prices for VXX and SVXY from inceptions of the ETNs through December 2019, we find that: (more…)