Paired Switching: Head-to-Head Asset Rotation

Paired switching is an allocation method that continuously rotates between two complementary assets based on relative momentum. The portfolio holds whichever asset has shown stronger recent returns and switches when leadership changes. The concept, introduced by Lewis Glenn (SSRN #2437049), exploits the tendency for complementary asset classes — particularly stocks and bonds — to exhibit alternating leadership during different market regimes.

How It Works

Each month, two assets are compared by their trailing returns over a specified lookback period. The asset with the higher return receives 100% of the portfolio. There is no protective mechanism, no cash option, and no partial allocation — the portfolio is always fully invested in one of two assets. When relative leadership shifts, the portfolio transitions completely to the new leader.

Why Pairs Work

The effectiveness of paired switching depends on the relationship between the two assets. The classic pairing — US equities (SPY) and long-term Treasuries (TLT) — works because these assets have historically exhibited negative correlation during periods of market stress. When equities decline due to economic weakness or rising risk aversion, the flight-to-quality effect drives bond prices higher. The momentum signal captures this rotation, moving the portfolio from the declining asset to the appreciating one.

This relationship means the paired portfolio always has access to an asset that is likely performing well — either equities during risk-on environments or bonds during risk-off environments. The momentum signal's role is simply to identify which regime is currently prevailing and position accordingly.

Strategies That Use Paired Switching

• Paired Switching (PAIRED) — SPY vs TLT by 3-month relative strength
• Composite Dual Momentum (CDM) — four independent pairs, each running its own paired rotation
• Quint Switching (QUINT) — extends the concept to 5 assets with trend confirmation

Limitations

Paired switching assumes that one of the two assets is always worth holding. This assumption breaks during rare periods when both assets decline simultaneously — as occurred in 2022 when rising rates caused both equity and bond prices to fall. Without a cash alternative, the strategy holds whichever asset is "less bad," absorbing losses from both sides of the pair. This limitation has motivated extensions like ADM-IP, which adds a second defensive option to handle environments where the primary pair fails.