Sequence of Returns Risk: The Quiet Killer

Two people retire on the same day with the same amount saved. They earn the exact same set of returns over five years and withdraw the same amount each year. One ends up with 90,986; the other with 80,586 (in any currency). The only difference between them is the order the returns arrived in. That gap of more than 10,000 is sequence of returns risk in a single picture, and a sequence of returns calculator lets you test it against your own figures.

It is one of the few ideas in retirement planning that feels almost unfair the first time you see it. You did everything right, you earned a perfectly respectable average, and the outcome still hinges on luck you had no control over. This guide explains what sequence of returns risk is, why it bites hardest in the first decade of drawing down a portfolio, and how the calculation actually works. A worked example walks through every step, so you can reproduce the numbers yourself.

What is sequence of returns risk?

Sequence of returns risk is the danger that the order of investment returns, rather than their average, damages a portfolio that is being drawn down. When money is being withdrawn each year, poor returns early on force the sale of more units to fund those withdrawals, leaving fewer units to recover when markets eventually rebound. The same returns in a kinder order leave the portfolio far healthier. Average return alone hides this completely, which is exactly why two retirees with identical averages can finish in very different places.

Put simply: the average tells you how the journey went on paper, but it says nothing about when the rough patches landed. In retirement, timing is everything.

Why sequence of returns risk matters

During the saving years, order barely registers. If no money is being added or removed, a set of returns produces the same ending balance no matter how you shuffle them, because multiplication does not care about order. The picture changes the moment regular withdrawals begin.

Once a portfolio is funding living costs, every withdrawal taken during a downturn locks in a loss that can never be undone. Sell units while prices are low and they are simply gone; when the recovery arrives, it acts on a smaller base. Research bodies that study retirement income consistently point to the years immediately before and after the start of drawdown as the period of greatest vulnerability. A weak first few years can meaningfully shorten how long a portfolio lasts, even when the long-run average looks perfectly healthy. That is why the concept matters most to people within roughly ten years either side of stopping work, and why it deserves attention long before the first withdrawal is taken.

How sequence of returns risk is calculated

There is no single magic formula. Sequence of returns risk is measured by running the portfolio forward year by year, applying each year's return and then the withdrawal, and comparing the ending balance under different orderings of the same returns. The core recursion looks like this:

Balance_end_of_year = (Balance_start_of_year x (1 + r)) - W

Where:

Balance_start_of_year = the portfolio value at the start of the year
r = that year's return, as a decimal (for example 0.07 for 7%)
W = the withdrawal taken at the end of the year

You repeat this for every year of the projection. To expose sequence risk, you run the identical list of returns in two or more orders and compare the final balances. The wider the spread between them, the more sequence risk the withdrawal plan is carrying.

A worked example with real numbers

Consider two retirees, each starting with 100,000 (in any currency) and withdrawing a fixed 5,000 at the end of every year for five years. Both experience the same five annual returns: +22%, +15%, +5%, −10% and −15%. Those returns have an arithmetic mean of 3.4% a year. The only difference is the order they arrive in.

Retiree A gets the strong years first:

Year 1: 100,000 x 1.22 = 122,000, minus 5,000 = 117,000
Year 2: 117,000 x 1.15 = 134,550, minus 5,000 = 129,550
Year 3: 129,550 x 1.05 = 136,027.50, minus 5,000 = 131,027.50
Year 4: 131,027.50 x 0.90 = 117,924.75, minus 5,000 = 112,924.75
Year 5: 112,924.75 x 0.85 = 95,986.04, minus 5,000 = 90,986.04

Retiree B gets the same returns reversed, with the weak years first:

Year 1: 100,000 x 0.85 = 85,000, minus 5,000 = 80,000
Year 2: 80,000 x 0.90 = 72,000, minus 5,000 = 67,000
Year 3: 67,000 x 1.05 = 70,350, minus 5,000 = 65,350
Year 4: 65,350 x 1.15 = 75,152.50, minus 5,000 = 70,152.50
Year 5: 70,152.50 x 1.22 = 85,586.05, minus 5,000 = 80,586.05

Both withdrew 25,000 in total. Both earned the same average return. Yet Retiree A finishes with 90,986 and Retiree B with 80,586, a difference of about 10,400, leaving Retiree B roughly 11.4% worse off. To confirm that withdrawals are the cause, run the same returns with no withdrawals at all: both orders end at the identical 112,696. The divergence appears only when money is being taken out.

Why the two paths diverge

It helps to understand the mechanism rather than just observe the result. With no withdrawals, the ending balance is simply the starting amount multiplied by every annual growth factor, and because those factors can be multiplied in any order, the result is fixed. In this example that product is 1.12696, so 100,000 grows to 112,696 whichever way the years are arranged. The compound, or geometric, return works out at about 2.42% a year — notably lower than the 3.4% arithmetic mean, which is itself a useful reminder that averages flatter volatile returns.

Withdrawals break the symmetry. Taking money out each year means the balance that gets multiplied by the next return is no longer the same across the two orderings. When Retiree B suffers losses first, the withdrawals fall on an already-shrunken pot, and the strong later years then compound a smaller base. Retiree A's early gains, by contrast, give the withdrawals more room to come from growth rather than capital. The arithmetic of compounding is unchanged; what changes is the size of the balance each return gets to act on once cash is leaving the account.

How to use the sequence of returns calculator

The sequence of returns calculator automates the year-by-year recursion above so you do not have to grind through it by hand. You enter a starting balance, an annual withdrawal (or a withdrawal rate), and a series of expected or historical returns. The tool then projects the balance forward and lets you reorder or stress-test those returns to see how sensitive the outcome is to a poor early run.

The outputs typically include the ending balance, the year the portfolio would be exhausted under a worst-case ordering, and a side-by-side comparison between favourable and unfavourable sequences. Reading those together shows how much of the outcome rests on timing rather than average performance. Pairing it with a safe withdrawal rate calculator helps you test whether a chosen withdrawal level holds up across different orderings, not just the one comfortable projection.

Common scenarios

Retiring just before a downturn

Someone who stops work and then meets a sharp market fall in year one or two faces the most punishing version of this risk. Withdrawals during the fall sell units cheaply, and the later recovery acts on a smaller base. This is the textbook bad-luck case, and it is the one worth stress-testing hardest.

Flexible versus fixed withdrawals

A retiree who can trim spending in weak years sells fewer units at low prices. A fixed withdrawal, by contrast, takes the same amount regardless of market conditions and so concentrates sequence risk. Even modest flexibility in the early years can change the picture more than people expect.

A cash buffer in the early years

Holding a separate pot of cash to fund the first couple of years means the invested portfolio is not forced to sell into a downturn. This is one of the more common ways people try to blunt early-sequence damage, buying time for markets to recover before drawing on the invested pot.

Still saving, not yet drawing

For someone years away from drawdown, order is largely irrelevant. The same return set produces the same balance in any order, so sequence risk is effectively dormant until withdrawals start. A saver may even quietly benefit from a poor early run, buying cheap units that grow later.

Common missteps

Judging a plan on average return alone — the average can look perfectly fine while a bad early run quietly drains the portfolio underneath it.
Assuming the accumulation rules still apply — order does not matter while saving, but it matters a great deal once withdrawals begin.
Taking fixed withdrawals through every market — rigid withdrawals in a downturn lock in losses that a more flexible approach might soften.
Ignoring the first decade — the years around the start of drawdown carry far more weight than the ones that follow.
Testing only one return path — a single smooth projection hides the risk entirely; comparing several orderings is what reveals it.

Frequently asked questions

What is sequence of returns risk in simple terms?

Sequence of returns risk is the chance that the order in which investment returns arrive harms a portfolio that is being drawn down, even when the average return is healthy. When you withdraw money each year, a run of poor returns early on forces you to sell more units at low prices, leaving less to recover when markets improve. The same returns arriving in a kinder order leave you far better off. It is purely a timing effect: two portfolios with identical average returns can end up far apart simply because one met its weak years first while the other met them last.

Why does the order of returns only matter in retirement?

The order of returns matters once money is being withdrawn because withdrawals interact with each year's balance. While you are saving and adding money, a set of returns produces the same ending value in any order, since you are only multiplying. Once you start taking money out, a withdrawal during a downturn permanently removes units that would otherwise have recovered. That is why sequence risk is dormant during the saving years and becomes most dangerous in the first several years of drawdown, when the portfolio is largest and most exposed.

How can sequence of returns risk be reduced?

Several approaches come up often. Holding a cash buffer to cover the first year or two means the invested portfolio is not forced to sell into a falling market. Keeping withdrawals flexible, so spending dips a little in weak years, reduces the units sold cheaply. Diversifying across assets that do not all fall together can smooth the early path. None of these eliminate the risk, but each can soften an unlucky early sequence. A sequence of returns calculator lets you test how much difference each adjustment makes against your own figures before committing to a plan.

Does sequence of returns risk affect people who are still saving?

For people still building a portfolio with no withdrawals, sequence of returns risk is largely irrelevant. Because contributions are going in rather than out, the same set of returns produces the same ending balance regardless of order. In fact, a saver may benefit from poor early returns, as they buy more units cheaply that grow later. The risk switches on when the cash flow reverses and regular withdrawals begin, which is why it is framed as a retirement and drawdown concern rather than an accumulation one.

Sources and methodology

The worked example was calculated using the standard year-by-year drawdown recursion, applying each annual return before the withdrawal, and verified by running the same returns in reversed order to isolate the timing effect. The figures reproduce exactly, and the no-withdrawal control was checked independently to confirm the 112,696 result holds in both orders. The concept and its emphasis on the early drawdown years are drawn from global retirement-income research:

OECD Pensions Outlook — analysis of retirement income and drawdown risk
CFA Institute Research Foundation — literature on withdrawal strategies and sequence risk

The bottom line

Sequence of returns risk shows that an average return tells you very little once you are living off a portfolio. The same five returns left one retiree with 90,986 and another with 80,586, a gap created entirely by timing. None of this means markets must be predicted, which they cannot be; it means a withdrawal plan deserves to be stress-tested against unlucky orderings rather than a single smooth projection. Running your own numbers through a sequence of returns calculator, alongside a Safe Withdrawal Rate Calculator — Retirement Income, is a practical way to see how durable a plan really is before the first withdrawal is ever taken.

A few related tools cover the numbers on either side of this one:

Safe Withdrawal Rate Calculator — Retirement Income — Sustainable annual withdrawal from retirement portfolio.
Portfolio Drawdown Calculator — How long savings last at a given spend rate.