What is sequence-of-returns risk?

It is the risk that the order of your investment returns, not just their average, decides whether your money lasts. Once you are withdrawing, poor returns early do permanent damage: you sell more shares at low prices to fund the same spending, and those shares are not there to recover when the market does.

Why does the order of returns matter if the average is the same?

It does not matter at all while you are saving — multiplication does not care about order, so the same returns in any sequence give an identical final balance. It matters enormously once money is coming out, because withdrawals interact with the balance at the time they are taken.

When is sequence-of-returns risk highest?

In roughly the first ten years of retirement, and most acutely in the first five. That is when the portfolio is largest, the withdrawal is a claim on a balance that has no time to recover, and there are still decades of spending ahead.

How do I protect against a bad sequence?

Flexible spending is the most effective defence: a plan that can cut discretionary spending in a bad year sells far fewer shares at the bottom. Holding a cash or short-bond buffer for early withdrawals, delaying Social Security to raise guaranteed income later, and part-time income in the early years all work on the same mechanism.

Sequence-of-returns risk, and why averages lie

The same ten years of market returns, in a different order, leave one retiree with $1.4 million and another with $708,000. Nothing changed but the order — and that is the risk no average return can show you.

Retirement projections that use an average return share one flaw, and it is not a small one. They assume the market delivers its average every year in turn. It never has, and the difference between “8.5% a year” and “these ten years in this order” is the difference between two retirements.

The clearest way to see it is to take one set of returns and change nothing except their order.

The same ten years, twice

Here are ten annual returns: 22%, 15%, 28%, −18%, 19%, −3%, 11%, −12%, 6%, 17%. Their arithmetic mean is 8.5%. Below they appear twice — sorted best-first, then worst-first. It is the same set of numbers both times, so the average is identical by construction.

Both retirees start with $1,000,000 and withdraw $60,000 a year.

Year	Return	Good years first	Return	Bad years first
1	28%	$1,203,200	-18%	$770,800
2	22%	$1,394,704	-12%	$625,504
3	19%	$1,588,298	-3%	$548,539
4	17%	$1,788,108	6%	$517,851
5	15%	$1,987,325	11%	$508,215
6	11%	$2,139,330	15%	$515,447
7	6%	$2,204,090	17%	$532,873
8	-3%	$2,079,767	19%	$562,719
9	-12%	$1,777,395	22%	$613,317
10	-18%	$1,408,264	28%	$708,246

One retiree finishes the decade with $1,408,264. The other finishes with $708,246 — roughly half — having earned exactly the same returns, at the same average, spending the same amount. The only difference is which years came first.

Why the saver does not have this problem

Now run the identical sequences with no withdrawals, as though these were the last ten years before retirement rather than the first ten after:

Good years first: $2,059,195
Bad years first: $2,059,195

Identical. Not approximately — exactly, because multiplying a balance by the same ten factors in any order gives the same product. Order is mathematically irrelevant when nothing is coming out.

That contrast is the whole concept. Sequence risk is not a property of markets; it is a property of withdrawing from markets. It switches on the day you retire, which is precisely when most people stop paying attention to it.

The mechanism, in one sentence

When you withdraw a fixed amount during a fall, you sell more shares to raise it — and those shares are permanently gone, so they are not there to participate in the recovery. The loss is not the paper decline; it is the shares you had to hand over at the bottom to pay for a normal year of your life.

This is why the danger concentrates in the first decade of retirement, and most sharply in the first five years: the balance is at its largest, each withdrawal is a claim against a portfolio with no time to recover, and there are still twenty-five or thirty years of spending to fund afterwards. The same crash at 85 is uncomfortable. At 63 it can reshape everything that follows.

What actually helps

Spending you can flex. The most powerful defence by some distance. Knowing which part of your budget is essential and which is discretionary means a bad year cuts the second — and you sell far fewer shares at the worst possible price. Note that the classic 4% studies assume you cannot do this, which is one reason they are conservative.
A buffer for early withdrawals. Holding a couple of years of spending in cash or short bonds means the first bad year can be funded without selling equities into it.
Delaying Social Security. A larger inflation-adjusted income for life reduces how much the portfolio has to produce in every later year — see claiming at 62, 67, or 70.
Any earned income early on. Part-time work in the first years is worth far more than the same money later, because it relieves exactly the withdrawals that do the damage.

Why our projections are not a single average

This is the reason Retirement Buddy runs a Monte Carlo simulation rather than compounding one expected return. Each of the 2,000 paths draws its own sequence of returns and inflation, so the poor-sequence futures are actually present in the result instead of being averaged away.

When a plan shows an 85% probability of success, the failures in that 15% are mostly not exotic — they are ordinary decades with the bad years at the front. That is also why retiring before Social Security begins scores so much worse across our can-I-retire pages: those early years are full-rate withdrawals with no other income arriving, which is the exact condition this risk feeds on. What the resulting percentage does and does not mean is covered in what a success probability actually means, and the full assumption list is on the methodology page.