Sequence of Returns: Why a Crash Hurts More at the Finish Line

Tier 2 · Saving & Growing · intermediate · ~7 min read · investingreturnsriskretirementsaving

The number that hides a second story

Two investors put money into the same market over the same 25 years. They earn the exact same returns — the same average, the same single brutal crash year. One ends up with far more money than the other.

How? They didn’t get the crash at the same time. One lived through it early; the other got hit near the finish line.

This is sequence-of-returns risk: the order returns arrive in can change your outcome, even when the average is identical. It’s one of the most under-appreciated ideas in investing, partly because it seems like it shouldn’t be true — and partly because which direction it cuts depends on whether you’re adding money or spending it. Get the intuition right and a scary-sounding early crash can turn into the best thing that ever happened to your portfolio.

First, the case where timing doesn’t matter at all

Start with the simplest situation: you invest a single lump sum, then never touch it. Buy and hold.

Here, timing is completely irrelevant, and the reason is just arithmetic. Your ending value is your starting amount multiplied by each year’s growth factor:

$\text{start} × (1 + r_1) × (1 + r_2) × … × (1 + r_n)$

Multiplication doesn’t care about order. A 35% crash is a multiply-by-0.65 whether it happens in year 2 or year 22 — slide that factor anywhere in the product and the answer is unchanged. A buy-and-hold lump sum is immune to sequence risk.

So if timing never mattered, this lesson would be over. The twist is that almost nobody just holds a single lump sum. You add to your investments out of every paycheck. You draw an income in retirement. The instant money flows in or out along the way, timing comes alive.

Slide the crash and watch your finish move

The simulator gives you an otherwise-steady market — a normal return every year — and drops one crash into it. You decide how big the crash is and, with the last slider, which year it strikes. The teal curve plots your ending balance as a function of when the crash hits, and the faint dashed line is the ceiling you’d reach if it never crashed at all. The warm band between them is the crash’s damage.

Things worth trying

• Drag “Crash strikes after” from early to late. Your dot slides down the curve. The same crash that barely scratched you in year 2 carves a crater near the finish. Notice the damage band widening to the right — that’s sequence risk, drawn.
• Drag “Added each year” down to $0. Now it’s a pure lump sum, and the curve goes flat — timing stops mattering entirely. With no money flowing in, the crash multiplies your pile by the same amount wherever it lands. This is the buy-and-hold immunity from the arithmetic above.
• Put the contribution back and deepen the crash. A bigger drop tilts the curve harder: the more severe the crash, the more its timing matters.
• Lengthen the horizon. A crash early in a 40-year accumulation is almost free — decades of cheap buying erase it. The same crash with three years left to retirement is a disaster.

Why a saver wants the crash early

Here’s the counterintuitive heart of it. When you’re accumulating — adding money year after year — you should want the bad year to come early. Three things are happening at once:

1. Early on, your balance is small. A 35% drop in year two hits a few thousand dollars. The same drop in year twenty hits a fortune. An early crash barely scratches you.
2. A crash puts your future contributions on sale. Every dollar you invest during the slump buys in at depressed prices — more shares for the same money. You’re a buyer, and buyers want low prices.
3. You have years to recover. An early crash leaves decades for the rebound to compound; a late one doesn’t.

Put those together and the curve can only slope one way: the later the crash, the worse your finish. It’s the same machine that makes dollar-cost averaging work — a long accumulator turns volatility from a threat into a discount.

The mirror image: why a retiree fears the crash early

Now run the tape backwards. A retiree isn’t adding money — they’re withdrawing it. For them, sequence risk flips to its dangerous side: a crash in the first few years of retirement is the worst case, because they’re selling shares at low prices to fund living expenses, permanently shrinking the base that has to recover. Two retirees with the identical average return can have wildly different fates depending purely on whether the crash came at 66 or at 86.

That’s not a different rule — it’s the same rule, seen from the other side of the cash flow. Money flowing in wants the crash early; money flowing out wants the crash late. We give the withdrawal side its own playground in the retirement planning lesson, where a bad start can drain a nest egg decades sooner than the average would suggest.

What this changes about how you invest

• Don’t fear an early bear market — if you’re still contributing, welcome it. A crash in your twenties or thirties, while you keep investing through it, is a years-long discount on the assets you’re accumulating. The investors who panic-sell into it trade that gift away. Staying the course isn’t just discipline; the math is quietly on your side.
• “Average return” is an incomplete promise. A plan that assumes “7% a year” buries the fact that the path matters once you’re adding or spending money. Two paths to the same average can leave you in very different places. Be suspicious of any projection that shows a smooth line — the real world is jagged, and the jags interact with your cash flow.
• Sequence risk is why retirement glide-paths exist. Because the danger concentrates around the transition from saving to spending — exactly when your balance is largest and a crash would do the most damage — the textbook defense is to gradually de-risk as you approach retirement, trading some growth for protection. Young and accumulating, you can largely ignore timing; near and past retirement, it becomes a central risk to manage.

The habit to keep

If you’re young and steadily investing, internalize the most liberating implication of this lesson: a market crash is not your enemy — it’s a sale. Keep buying through it, automatically, and the timing works for you. The people who get hurt by sequence risk in the accumulation phase aren’t the ones who lived through a crash; they’re the ones who stopped contributing — or sold — in the middle of it.

And as you near the day you’ll start drawing an income, remember the rule flips. The thing you could safely ignore for decades — when the crash comes — becomes the thing to plan around. Same math, opposite sign, depending on which way your money is flowing.

Key terms

• Sequence-of-returns risk — the risk that the timing of returns, not just their average, changes your outcome. It only bites when money is flowing in or out; a buy-and-hold lump sum is immune.
• Accumulation phase — the years you’re adding money to your investments. Here, a crash early is an advantage.
• Decumulation (drawdown) phase — the years you’re withdrawing money. Here, the risk reverses: a crash at the start is the danger.
• Glide path — a strategy that gradually shifts a portfolio from growth assets toward safer ones as retirement approaches, precisely to blunt sequence risk near the transition.
• Dollar-weighted vs. time-weighted return — the market’s time-weighted return ignores your cash flows; your dollar-weighted return reflects when you actually added or removed money. The gap between them is sequence risk in a number.

You’ve now seen volatility from three angles: as a discount you can average into, as the price of higher returns, and — here — as a timing risk that interacts with your cash flow. Next we leave the saving-and-growing phase behind and start applying all of it to the biggest money decisions of a life: renting versus buying, mortgages, taxes, and when to finally stop working.