Sequence-of-returns risk
The 4 % rule gives you a target number, but it hides the most real danger of early retirement: what matters isn't just your portfolio's average return, but the order in which the good and bad years arrive. While you are accumulating, the order is irrelevant. The moment you start withdrawing, it changes everything.
Same average, two opposite fates
Imagine two people who retire with €500,000, withdraw €20,000/year (inflation-adjusted) and earn exactly the same average return over 30 years. The only difference: one suffers the big drops early and the other late.
- Drops early: they sell cheap units precisely when the portfolio is crushed, just to pull out their €20,000. Those units won't be there to recover in the rebound. The portfolio can be depleted prematurely.
- Drops late: the early good years grow the capital; when the drops arrive, there's already a huge cushion. They end with more money than they started.
Same returns, same average, same spending. The order is what separates ruin from abundance. This is sequence-of-returns risk.
Why withdrawing flips the logic of compounding
When you contribute, a drop is an opportunity: you buy cheap. When you withdraw, a drop is a wound: to pull out the same amount in euros you must sell more units, and you sell the ones you'll miss most in the recovery. It's compound interest working against you. That's why the first 5-10 years of withdrawal are the maximum-danger zone: a bad run right there marks the difference for the following three decades.
Mitigation 1: cash buffer (cash bucket)
Keep 1 to 3 years of expenses in something safe and liquid —a savings account or deposit, Treasury bills—, separate from the invested portfolio. In a down year you spend from that bucket instead of selling crushed equities. When the market recovers, you refill it. It doesn't remove the risk, but it gives you room not to sell at the worst moment.
Cost: that money doesn't compound at stock-market pace. It's the price of the insurance. 1-3 years is usually the balance; a bigger bucket means more drag on returns.
Mitigation 2: bond tent
A glide path shaped like a tent around your retirement date: you raise the bond weight in the years before and the first years of withdrawal (when sequence risk peaks) and then, if markets cooperate, you let equities rise again. You enter the danger zone with a more defensive portfolio (e.g. 40-50 % bonds) and, once the critical early years pass, let equities take the lead again (rising equity glide path).
Mitigation 3: spend flexibly
The most powerful and cheapest defence: trim the withdrawal in bad years. If in a 30 % drop you cut spending by 10-15 % (skip the big trip, postpone the car), you avoid selling at lows and drastically improve portfolio survival. It's the basis of dynamic withdrawal strategies.
Common mistakes
- Retiring 100 % in equities right at a peak with no buffer. A drop in year 1 can be irreversible.
- Holding a giant cash bucket "just in case". Five years in cash drag returns so much they raise another risk: falling short to inflation.
- Treating the 4 % rule as autopilot. It works on average; your specific retirement happens only once, with its particular sequence.
What to do
Arrive at the date with an already more defensive portfolio, a 1-3 year expense buffer and an explicit plan to spend less if the first two years are bad. You don't need to predict the future; you need a bad start not to force you to sell what should recover.
Educational information, not financial or investment advice. Past results don't guarantee future ones; consult a professional for your retirement plan.