Why a 50% Loss Needs a 100% Gain to Break Even
Why a 50% Loss Needs a 100% Gain to Break Even
Here’s a piece of math that catches a lot of people off guard: losses and gains aren’t mirror images of each other. Lose 20%, and you don’t need a 20% gain to get back to even — you need 25%. Lose 50%, and it’s not a 50% gain that gets you back — it’s 100%.
That’s not a quirk of any particular investment. It’s simple arithmetic, and it applies to any portfolio, any account, any market. The deeper the loss, the more disproportionately large the recovery has to be — and understanding why matters a great deal more once you’re retired than while you’re still working.
The Math, Made Concrete
Start with $100,000. A 20% loss brings it to $80,000. To get back to $100,000 from $80,000 isn’t a 20% gain — it’s a 25% gain, because you’re now calculating growth off a smaller base.
Push the loss further and the gap widens fast. A 40% loss takes $100,000 to $60,000 — and getting back to even from there requires a 66.6% gain. A 50% loss takes it to $50,000, and the recovery needed is a full 100%. The chart below shows all three side by side.
Why This Matters More in Retirement
While you’re still working and contributing, a downturn like this is uncomfortable but rarely catastrophic. You have time for the recovery to happen, and new contributions keep adding to the base while it does.
Retirement removes both of those advantages at once. There’s less time left for a slow recovery to play out, and instead of adding to the account, you’re very likely withdrawing from it — which means the recovery has to outrun ongoing withdrawals just to keep the account from shrinking further. That combination is what turns this math from an interesting fact into a real planning risk, and it’s the same underlying mechanism behind what’s often called sequence of returns risk: the same average return, over the same number of years, can produce very different outcomes depending on when the good years and bad years happen to land.
This isn’t a reason to avoid market exposure altogether — growth is still an important part of most retirement plans. It’s a reason to think deliberately about which parts of a plan can afford to ride out a downturn like this, and which parts genuinely can’t.
Related Reading
This same mechanism, applied to a real historical decade, is what we walked through in Market Resilience: What History Teaches Us. And for a look at how this plays out for a specific family — including what structuring a portion of a plan around a guaranteed income floor can do about it — see One Decision, Two Outcomes: A Retirement Case Study.
If it’s been a while since anyone walked you through how a downturn — whenever it comes — might actually affect your own timeline, I’d be glad to have that conversation.