How do I build an ETF strategy that matches my risk profile and horizon?

Start from your stage of life

The Monte Carlo Simulator offers four reference profiles tied to life stage: young saver (100% Global Equities), family in accumulation (80% Equities · 20% Cash), approaching retirement (60% Equities · 40% Cash), and income/drawdown. Pick the one closest to your situation as a starting point, apply its parameters in one click, and check against 50 years of real historical data whether that allocation meets your expectations — you can freely adjust every value afterwards.

Stage of life isn't everything: what else to consider

Two people the same age, with the same demographic profile, can have very different risk capacity. Beyond stage of life, it's worth considering:

• Income stability: a stable salaried income supports a more aggressive equity allocation than variable or self-employed income, because it reduces the likelihood of having to sell investments at an unfavourable moment due to unforeseen needs.
• Other assets already held: if you already own property outright or are entitled to a substantial state pension, your ETF portfolio can afford a more aggressive allocation, since it isn't your only source of future financial security.
• Family circumstances: dependants, a large mortgage, or near-term spending goals (a purchase, children's education) call for a larger cash cushion and more caution than for someone without these commitments.
• Existing safety net: an emergency fund already in place, separate from the investment portfolio, lets you weather market downturns without having to sell equities at the worst possible moment.

The real test: how much can you lose without abandoning the strategy

Risk isn't an abstract number on paper — it's your actual ability to stay invested when the portfolio drops 30% or more. As a concrete reference: in 2008 global equity markets lost roughly 40-50% from their peak, in March 2020 around 30% in a matter of weeks, and in 2022 both equities and bonds fell at the same time for the first time in decades. Before choosing an allocation, ask yourself honestly: if your portfolio dropped by that much tomorrow, would you stick to the plan, or sell in a panic?

If the honest answer is "I'd sell", the equity allocation you're considering is probably too aggressive for you, regardless of what the stage-of-life profile suggests — a lower expected return you can psychologically sustain always beats a theoretically better strategy you can't actually follow through on.

Verify, don't guess

The stage-of-life starting point is a guide, not a fixed rule: your true risk tolerance, your specific time horizon, and your goals (growth, protection, income, drawdown) may call for adjustments. Use the simulator to test different combinations of equity allocation, rebalancing thresholds and regular contribution amounts, watching how the P15/P50/P85 scenarios move over a 50-year historical horizon — until the result feels consistent with what you're actually prepared to accept in terms of capital swings.

How to read the three P15/P50/P85 scenarios

The simulator ranks the results of thousands of historical simulations and presents them as three reference scenarios. The Median Scenario (P50) is the result half the simulations exceed and half fall short of — the main reference point, neither optimistic nor pessimistic. The Cautious Scenario (P15) is only reached by the worst 15% of simulations: it represents an unfavourable market, and it's the one to use as a "fallback plan" — your portfolio, and your strategy, need to hold up there too. The Favourable Scenario (P85) is only exceeded by the best 15%: useful for understanding the upside, but not something to base decisions on.

In practice: if the P15 result isn't acceptable for your situation — because it's too low relative to your goals, or because the path to get there passes through drops you couldn't tolerate — it's the strategy that needs revisiting, not your judgement about the P15. Reduce the equity share, extend the time horizon, or lower the planned annual withdrawal during drawdown.

Adjusting rebalancing thresholds and regular contributions

Equity allocation isn't the only parameter that affects the outcome: the simulator also lets you test rebalancing thresholds (how far a component needs to drift from target before you act) and the size of regular contributions. Tighter thresholds generate more transactions and more transaction/tax costs, but keep the portfolio closer to target; wider thresholds cut costs but allow bigger swings before you step in. For more on choosing thresholds, see the dedicated FAQ When and How Should I Rebalance My ETF Portfolio?

The amount and frequency of regular contributions also affect the final outcome: more regular, consistent contributions over time tend to average out the purchase price better than irregular contributions concentrated in a few moments, especially over longer time horizons.

Revisit the strategy when your stage of life changes, not every week

It makes sense to revisit your allocation when your situation changes substantially: a shift in stage of life (from accumulation toward retirement, from income to genuine drawdown), a major event (a significant job change, an inheritance, the birth of a child), or a lasting change in your perceived risk tolerance after living through a genuine market downturn.

It doesn't make sense, however, to change your allocation in response to short-term market moves — a 10% drop this month isn't a signal to become more cautious, just as a rally isn't a reason to take on more risk. This kind of reactive adjustment, driven by the emotion of the moment, is often the main cause of worse outcomes compared with simply sticking to the established plan.

Practical checklist

• Start from the stage-of-life profile closest to your situation as a starting point, not a final answer.
• Factor in income, other assets, family circumstances and any existing safety net, not just age.
• Ask yourself honestly how you'd react to a 30-40% drop, before choosing your equity allocation.
• Use the simulator to test different combinations, and always check the P15 scenario, not just the P50.
• Test rebalancing thresholds and contribution amounts too, not just the equity allocation.
• Revisit the strategy at stage-of-life changes or major events, not in response to short-term market moves.