Why Horizon Shapes Allocation
Why Horizon Shapes Allocation
A 50% drawdown always requires a 100% gain to break even. Time doesn't change the math, but it makes recovery possible.
Key takeaways
- A 50% loss requires a 100% gain to recover; a 30% loss requires a 43% gain. The math is relentless.
- Longer horizons allow you to stay invested through the gain phase and realize the recovery.
- Shorter horizons often force you to sell during the loss phase, crystallizing losses and missing recoveries.
- The relationship between drawdown size and recovery time is empirical: larger crashes historically take longer to recover from.
- This asymmetry between loss and recovery is why allocation is tied directly to time horizon.
The arithmetic of loss and recovery
Start with a simple example. You have £10,000. The market crashes 50%. You now have £5,000.
To get back to £10,000, you don't need a 50% gain. You need a 100% gain.
£5,000 × 1.50 = £7,500 (still underwater) £5,000 × 2.00 = £10,000 (breakeven)
This is basic mathematics, but it's the beating heart of why time horizon matters. The deeper the loss, the longer the recovery. Here are the recovery multiples required:
| Loss | Recovery Gain Needed |
|---|---|
| 10% | 11% |
| 20% | 25% |
| 30% | 43% |
| 40% | 67% |
| 50% | 100% |
| 60% | 150% |
A 60% crash (worse than 2008, where the UK fell about 48%) requires the portfolio to triple just to break even.
Time spent in drawdown vs. time spent recovering
Here's where horizon becomes critical. If you hold stocks, you will experience drawdowns. The question is whether you have the time to wait for the recovery.
Consider the 2008 crash:
- FTSE 100 fell 48% (March 2008 to March 2009 = 12 months of loss)
- Recovery took 4 years, 7 months (to March 2013, returning to pre-crash levels)
If you needed the money in 2010, you sold at the bottom, crystallizing the 48% loss. If you held until 2013, you recovered fully and then some (dividends included, the total return was strongly positive by 2013).
This isn't luck. It's the simple arithmetic of having time to receive the gains that offset the losses.
A 3-year horizon investor in early 2008:
- Year 1 (2008): Market crashes 48%. Portfolio: destroyed.
- Year 2–3 (2009–2010): Market recovers 30–40%. Portfolio: still negative, only halfway back.
- Withdrawal date arrives: £48,000 withdrawn instead of £100,000. Permanent 48% loss.
A 10-year horizon investor in early 2008:
- Year 1 (2008): Market crashes 48%. Portfolio: destroyed.
- Years 2–5 (2009–2012): Market recovers 80%+. Portfolio: now back to breakeven or better.
- Years 6–10 (2013–2017): Market delivers strong returns. Portfolio: far ahead of where it would have been if held in bonds.
- Withdrawal date arrives: Portfolio has recovered fully plus years of growth. Drawdown never materialized.
The same crash. The same portfolio. Different outcomes because of time.
Historical crash and recovery times
The evidence is scattered across 100+ years of market history:
1929–1939: US market fell 90%, took 25 years to recover (nominal). UK market fell similarly. A 3-year horizon would have been catastrophic; a 10-year horizon marginally worse.
1973–1974: UK market fell 55%, recovered in 4 years (1978). A 3-year horizon caught you at the bottom; a 5-year horizon saw full recovery.
2000–2002: FTSE 100 fell 47%, took 8 years to recover. A 5-year horizon would have been negative in 2005; a 10-year horizon would have been neutral-to-positive by 2010.
2008–2009: FTSE 100 fell 48%, recovered in 4 years, 7 months. A 4-year horizon caught you breakeven in 2013; a 10-year horizon saw 80%+ cumulative gains by 2018.
2022: FTSE 100 fell 26%, recovered in 14 months. A 1-year horizon was underwater; a 3-year horizon was strongly positive by 2024.
The pattern: larger crashes take longer to recover from. A 20% crash typically recovers in under two years. A 50% crash takes four to five years. A 90% crash takes decades.
Why this means different allocations for different horizons
The allocation of a portfolio is a bet on the recovery horizon exceeding the drawdown timing.
A 3-year horizon portfolio (short): You cannot afford a major drawdown. Your allocation must be 0% stocks. If a crash comes in year 1, you've lost 0% and recovered 0% (because you have no exposure). Safe, but you also get no equity upside.
A 5-year horizon portfolio (medium): You can absorb a moderate drawdown if you have time to recover. A 30% crash in year 1 means you're down £3,000 on a £10,000 portfolio. Years 2–5 you get typical equity returns (7–9% nominal). By year 5, the loss is fully recovered and exceeded. Allocation: 50–70% stocks.
A 15-year horizon portfolio (long): You can absorb a 50% crash in year 1. Years 2–15, even with below-average returns, you recover and compound substantially. A crash isn't a disaster; it's an opportunity to buy more equities at lower prices (if you rebalance). Allocation: 90–100% stocks.
The withdrawal trap: why you sell low
The cruel part of a short horizon is that you're often forced to withdraw money during the loss phase, not after the recovery.
Imagine you needed to withdraw £5,000 per year from a £100,000 portfolio for 10 years. You'd planned on 70/30 stocks/bonds, expecting 6% annual returns. But:
- Year 1: Market crashes 50%. Portfolio: £50,000. You still need to withdraw £5,000. You're selling from a portfolio that's half its value.
- Year 2: Market recovers 20%. You withdrew when it was bottomed. Your remaining portfolio is now £42,000 (after withdrawal), but you've permanently lost the opportunity to benefit from the recovery.
If you'd had a 15-year horizon instead:
- Year 1: Market crashes 50%. Portfolio: £50,000. You don't need the money yet.
- Year 2: Market recovers 20%. Portfolio: £60,000 (pre-recovery).
- Years 3–15: You benefit from the full recovery, plus ongoing growth.
- By year 10, you're ahead, not behind.
This is sequence-of-returns risk, explored later. But it flows directly from the mismatch between horizon and allocation: a short-horizon portfolio should never hold enough equities to suffer this trap.
The horizon-allocation formula
The relationship isn't arbitrary. Historically:
0–3 years: You can tolerate a 0% drawdown (i.e., you can afford no crash). Allocation: 0% equities. Expected return: inflation + 1–2% (roughly 2–3% nominal in a 2–3% inflation environment).
3–5 years: You can tolerate a 20–30% drawdown and still be positive by the end. Allocation: 40–50% equities. Expected return: 4–5% nominal.
5–7 years: You can tolerate a 30–40% drawdown. Allocation: 60–70% equities. Expected return: 5–6% nominal.
7–10 years: You can tolerate a 40–50% drawdown. Allocation: 70–85% equities. Expected return: 6–7% nominal.
10+ years: You can tolerate a 50%+ drawdown. Allocation: 85–100% equities. Expected return: 7–9% nominal.
Each step assumes a typical drawdown size and recovery time. If you hold an allocation beyond your horizon, you've over-risked. If you hold a lower allocation than your horizon allows, you've under-returned.
The flowchart
The logic is straightforward:
Related concepts
Next
The relationship between horizon and allocation is mathematical and empirical. But there's a second dimension: your willingness to tolerate risk, independent of your ability to recover from it. Some investors have 30-year horizons but can't sleep through a 20% crash. Others have 5-year horizons but can stomach 50% swings. That's where risk tolerance enters—and where personal values override the formula.