SPY - VIX Sub 20: The Short Volatility Trade Is Back April, 06 2021 09:39 AM SPDR S&P 500 Historically, the short VIX trade has been appropriate with VIX under 20. ProShares Short VIX ETF benefits from falling VIX. S&P 500 at extreme valuation is the major risk to the short VIX trade. For further details see: VIX Sub 20: The Short Volatility Trade Is Back