Sequence of Returns Risk

What Is It

Sequence of returns risk is the danger that the order your investment returns arrive in — not just their average — determines whether your money lasts through retirement. It only shows up once you’re withdrawing money, not just accumulating it: a market crash early in retirement forces you to sell more shares at depressed prices to cover the same withdrawal, permanently shrinking the portfolio that would otherwise have recovered when the market rebounded.

Why It Matters

This is exactly why the Trinity Study and the 4% Rule tested every rolling 30-year period in market history instead of just relying on one long-run average return — the sequence a retiree happens to experience is what actually determines survival, and nobody gets to pick which sequence they’re handed. The danger is heaviest in the first five to ten years of retirement: a portfolio that hasn’t been drawn down yet has more room to absorb a bad stretch than one that’s already shrinking from withdrawals.

Quick Example

Take two retirees with $1,000,000, each withdrawing $40,000 a year, both experiencing the exact same five annual returns over five years — just in a different order. One hits a −30% crash in year one, followed by four +20% years; the other has the identical four +20% years first, with the −30% crash arriving last. Same five numbers, same average return — but the crash-first retiree ends up with roughly $1.14 million, while the crash-last retiree ends up with roughly $1.24 million. About $100,000 apart, purely from timing.

Try It Yourself

A flat average-return calculator literally can’t show this risk — it needs to model real year-by-year sequences. That’s exactly what Monte Carlo simulation is for.

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