What is the Treasury Duration Limiter (TDL)?
Treasury Duration Limiter, TDL. A protective overlay built into several DMS strategies that steers the Risk Off holding into short-duration treasuries when long-duration treasuries look hazardous.
Why it exists
Several DMS strategies hold long-duration treasuries as their Risk Off asset. Historically, when equities fall, investors flee to long-duration treasuries, which drives their prices up and helps cushion market drawdowns. That relationship held reliably for decades, but it is not guaranteed. In early 2022, rising interest rates caused long-duration treasuries to fall at the same time as equities - one of the worst years on record for long-duration treasury returns. Strategies that rotated defensively into long-term treasuries in that environment found that the expected safe harbor was also under water.
TDL was developed in response to that reality. The goal: if long-duration treasuries look likely to be hazardous, steer into short-duration treasuries instead and avoid compounding a bad equity period with a bad treasury period.
How the signal works
TDL uses a momentum signal on long-duration treasuries themselves. It applies a weighted lookback to long-duration treasury returns, blending the trailing 1, 3, and 6-month results with half the weight on the 6-month leg. If that weighted result is negative - long duration is losing money on its own terms - TDL fires and the Risk Off allocation moves to short-duration treasuries.
The deliberate emphasis on the slower 6-month leg matters. The episodes TDL exists to catch are ones where long duration has been damaged for months but has just bounced. A faster, more recent-weighted formula would let a single flight-to-quality month veto the signal. Testing across 44 years of history confirmed this: weighting the most recent month more heavily caused TDL to miss both October 1987 and the 1994 bond massacre. The current weighting also sits on a wide plateau, meaning small changes to it produce identical results - a sign the setting is robust rather than tuned.
Once TDL fires, it stays fired
TDL is not re-evaluated every month. Once it fires within a Risk Off run, the short-duration position is locked and held for the remainder of that run. The lock clears only when the strategy returns to Risk On.
This is intentional. It prevents whipsawing back into long duration on a single-month reversal, and it produces a smoother path with fewer trades. The tradeoff is real: if long-duration treasuries rally later in the same Risk Off run, the strategy sits it out. That cost was measured and accepted.
What TDL does not do
TDL is only active when a strategy is already in its Risk Off, defensive position. It has no effect on equity allocations and does not determine when to enter or exit equities - that remains the exclusive domain of the strategy's momentum rules. TDL is purely a safety layer within the treasury sleeve.
Which strategies use it
TDL is built into the Global Navigator family (Global Navigator, 200, and 300) and the LT Gain family (LT Gain, 200, and 300). It is part of those strategies, not a separately configurable option.
Not every DMS strategy needs it. Triad, for example, was tested with four different TDL variants on its defensive sleeve and every one performed worse than leaving the sleeve alone. Global Navigator needs a TDL because it goes fully Risk Off for extended runs. Triad's defensive weight is much smaller and is already conditioned by three separate trend gates, so a second timing layer adds whipsaw rather than protection.