Paired Switching is proof that effective tactical asset allocation can be extraordinarily simple. This momentum strategy rotates your entire portfolio between just two assets based on which one has performed better recently. No complex math, no multi-factor models, no optimization — just a straightforward comparison of recent returns, applied monthly.
What Is Paired Switching?
Paired Switching is a relative momentum strategy that allocates 100% of the portfolio to whichever of two assets has the higher recent return. In its most common implementation, it switches between U.S. stocks and long-term Treasury bonds. When stocks are outperforming bonds, you hold stocks. When bonds are outperforming stocks, you hold bonds. That's it.
The strategy exploits the well-documented momentum anomaly — the tendency for recent winners to continue winning and recent losers to continue losing — applied to asset classes rather than individual stocks.
Who Created It?
The Paired Switching concept was published on Quantpedia and builds on research by Mebane Faber and others in the tactical asset allocation space. The key insight was demonstrating that simple pairwise comparison between negatively correlated assets (like stocks and bonds) could produce strong risk-adjusted returns without the complexity of multi-asset momentum systems. The approach is closely related to Faber's quantitative approach to tactical allocation published in his landmark 2007 paper A Quantitative Approach to Tactical Asset Allocation.
How Does It Work?
The monthly rebalancing process is as simple as it gets:
- At month end, compare the recent returns (typically 3 to 12 months) of U.S. stocks (SPY) and long-term Treasury bonds (TLT).
- Invest 100% in whichever asset has the higher return over the lookback period.
- Hold for one month, then repeat.
The strategy is always fully invested — it never goes to cash. The key insight is that stocks and bonds tend to have a negative or low correlation, so when one is trending down, the other is typically trending up. By always choosing the stronger trend, Paired Switching aims to capture upside from both asset classes while avoiding the worst drawdowns of each.
BestFolio implements the SPY/TLT variant, which is the most widely followed version and offers the longest backtest period.
Historical Performance
Based on BestFolio's backtest from September 1986 through March 2026 (nearly 40 years):
- CAGR: ~10.7%
- Maximum Drawdown: -33.1%
- Backtest Period: 39 years
A 10.7% CAGR over nearly four decades is remarkable for a strategy with just one rule and two assets. To put this in perspective, a Classic 60/40 delivered ~8.8% CAGR over a similar period, meaning Paired Switching added roughly 2 percentage points of annual return — which compounds to a massive difference over decades.
The -33.1% maximum drawdown is the trade-off. Because the strategy is all-in on one asset at a time, it can suffer when momentum reverses quickly. The 2020 COVID crash and 2022 rate shock both created whipsaw conditions where the strategy switched at unfavorable times.
Pros and Cons
Pros
- Maximum simplicity: One rule, two assets, monthly frequency — anyone can implement this.
- Strong historical returns: 10.7% CAGR beats most tactical and fixed allocation strategies.
- Built-in diversification: Rotates between negatively correlated assets.
- Low cost: Just two highly liquid ETFs with rock-bottom expense ratios.
- Easy to automate: The signal is binary and unambiguous.
Cons
- All-or-nothing: 100% concentration in one asset can be psychologically difficult.
- Whipsaw losses: Choppy, trendless markets cause frequent unprofitable switches.
- No absolute momentum filter: Unlike GEM, there is no mechanism to move to safety when both assets are falling.
- Significant drawdowns: -33.1% max DD is not much better than buy-and-hold stocks.
- Tax implications: Monthly switching can generate short-term capital gains.
Try It on BestFolio
Paired Switching is available as a free strategy on BestFolio. View the complete backtest, monthly signals, and current allocation. Compare it side-by-side with other momentum strategies to see how adding complexity affects returns and risk.
View Paired Switching on BestFolio →
Want to understand how momentum strategies work? Start with our guide to tactical asset allocation, or see how Paired Switching compares to more sophisticated dual momentum approaches in our dual momentum comparison.