February · The Decision Calendar

The Longevity Check

Alex Alston

The same thirty years of returns, run in three different orders. Identical averages — very different outcomes. This shows how much has to go wrong before your plan stops working, and how much of that risk you can take back.

01Your numbers From January's baseline
Would you actually adjust spending if the portfolio fell?

This applies guardrails: if your withdrawal drifts well above where it started, spending steps down about 10% and stays down until the portfolio recovers. If it drifts well below, spending steps up. It never falls below your essentials — and it only counts if you'd really do it.

02Three orders, one set of returns

Every scenario below uses the exact same thirty return figures — the only thing that changes is the order they arrive in. The averages are identical by construction.

Portfolio balance over time
Steady — no swings Rough start Strong start
03What this tells you

Carry forward

This is arithmetic on the assumptions you enter, not a forecast. Nobody knows what returns will be or in what order. The purpose is not to predict an outcome — it is to show how much the order matters, and how much of that exposure you can remove. Bring it to the February call.