Sequence of returns risk is the danger that the order in which your investment returns occur, not just their long-term average, determines how long a retirement portfolio lasts. Two retirees can earn the identical average return over the same period and end up with completely different account balances, because withdrawals interact with returns differently depending on when the losses happen.
Why Average Returns Don't Tell the Whole Story
An average return is just one number smoothed over many years. It treats a portfolio that lost 20% in year one and gained 20% in year ten the same way it treats one that did the reverse. For someone still adding money to an account, that's roughly true. For someone taking money out every year to live on, it isn't.
Here's the mechanic. When a retiree withdraws a set dollar amount during a down year, that withdrawal is drawn from a portfolio that has already shrunk. More shares or units have to be sold to raise the same cash, which permanently reduces how much is left to participate when the market eventually recovers. The loss gets locked in. A gain in a later year can't undo it, because it's now compounding on a smaller base. Run the same withdrawals through the same returns in reverse order, gains early, losses late, and the math works entirely differently.
A Simplified Illustration: Same Average Return, Different Order
Retirement researcher Michael Kitces, whose Nerd's Eye View analysis is widely cited in the financial planning industry, illustrates this with a deliberately extreme example built to isolate the effect of order. It is a hypothetical, not a record of real market history, and the figures are exaggerated on purpose so the mechanic is unmistakable.
Picture a $1,000,000 portfolio and a retiree who needs to withdraw $500,000 at the end of year one. The two scenarios below use the exact same two annual returns, +100% and -50%, just in opposite order.
| Scenario | Year 1 Return | Balance After Year 1 Withdrawal | Year 2 Return | Ending Balance |
|---|---|---|---|---|
| Gains first | +100% | $1,500,000 | -50% | $750,000 |
| Losses first | -50% | $0 | +100% | $0 |
Both retirees experienced the exact same two returns, so both had the exact same average return. One ends with $750,000. The other ends with nothing, because the withdrawal hit while the portfolio was already down, and a 100% gain on a $0 balance is still $0. Real portfolios rarely move by 100% or 50% in a single year. The illustration uses extreme numbers on purpose, so the effect isn't subtle, but a smaller version of the same mechanic plays out in ordinary market cycles too.
Why the First 5 to 10 Years of Retirement Carry the Most Risk
This isn't a new observation. William Bengen's landmark 1994 study, "Determining Withdrawal Rates Using Historical Data", was the research that first rigorously quantified how much the order of historical market returns, not just their average, affects whether a retirement portfolio survives. That paper is the foundation of the widely known "4% rule."
Kitces later took that research further and measured exactly how strongly early returns predict a retirement's outcome. Comparing a retiree's safe withdrawal rate against market returns over different stretches of time, he found the correlation to first-year returns alone was weak, just 0.21, while the correlation to real (inflation-adjusted) returns over the first ten years of retirement climbed to 0.79. Over the full thirty-year horizon, nominal returns showed essentially no relationship to the outcome, and even real thirty-year returns explained far less than the first decade did (a correlation of 0.43).
The reasoning holds up on its own. Money withdrawn early in retirement doesn't get another thirty years to compound, it's gone. Growth (or losses) in the first decade sets the base that every later year's return compounds against. A weak first ten years leaves a permanently smaller base for decades twenty through thirty to work with, while a strong first decade builds a cushion that can absorb a bad year later on far more easily.
Is Sequence of Returns Risk the Same as Market Risk?
No. Market risk is the general possibility that returns come in lower or more volatile than expected. Sequence of returns risk is narrower: it's about when that volatility shows up relative to your cash flows. A portfolio that is only being added to, with no withdrawals, doesn't really experience sequence risk in the same way; the ending value depends on the average return, not the order, because there's no cash leaving during the down years. It's the combination of withdrawals plus down markets, in a specific order, that creates the risk.
What Do Retirement Researchers Say About Managing This Risk?
Retirement income research has studied several general approaches to this problem: holding a short-term cash reserve so withdrawals don't have to come directly from a depressed portfolio ("bucket" strategies), using withdrawal rates that flex with portfolio performance instead of a fixed dollar amount, and adjusting how much of a portfolio sits in stocks versus bonds in the years right around retirement. These are findings from published research, not a personal recommendation, since the right approach depends on a person's specific accounts, other income, timeline, and risk tolerance.
How a Licensed Financial Advisor Can Help
Sequence of returns risk is easy to understand in a chart and much harder to plan around alone, especially in the years right before and after you actually stop working. A licensed financial advisor can look at your specific accounts, timeline, and other income, and help structure a withdrawal approach built to hold up against a bad sequence, instead of hoping the market cooperates in the order you need it to. Our retirement withdrawal calculator is a good starting point to see the general math, but it can't account for your specific sequence risk the way a licensed advisor can.
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