Using Wilder Volatility Stops to Time the U.S. Stock Market

Can investors use volatility signals to identify short-term stock market trend changes? In his February 2023 paper entitled “Using Volatility to Add Alpha and Control Portfolio Risk”, John Rothe uses Welles Wilder’s Average True Range (ATR) volatility metric to generate buy and sell signals for broad U.S. stock market indexes. Specifically, he each trading day:

1. Computes the true range of a broad equity exchange-traded fund (ETF) as the greatest of: (a) daily high minus low; (b) absolute value of daily high minus previous close; and, (c) absolute value of daily low minus previous close.
2. Calculates ATR as the simple average of the last five true ranges (including the current one).
3. Generates a Wilder Volatility Stop (WVS) by multiplying ATR by a factor of 2.5 as representative of investor volatility risk tolerance.
4. When out of the asset, he buys when the asset closes above a dynamic trendline apparently defined by a trend minimum plus current WVS (breakout). When in the asset, he sells when the asset closes below a dynamic trendline apparently defined by a trend maximum minus current WVS (breakdown).

He focuses on SPDR S&P 500 ETF Trust (SPY) during 2000-2010 (beginning of 2000 through 2009) but also looks at both Invesco QQQ Trust (QQQ) and iShares Russell 2000 ETF (IWM). In an appendix, he provides similar results for 2010-2020. He assume trades occur at the same closes as breakout and breakdown signals. He ignores effects of dividends and trading frictions. He uses buy-and-hold SPY as the benchmark for the strategy applied to SPY. Using daily raw (not dividend-adjusted) data for SPY, QQQ and IWM during January 2000 through December 2019, he finds that: (more…)