Position size: how much volatility you can actually sit with
Risk tolerance is not a personality quiz. It is the euro loss you can carry without selling at the worst time.
Isaak V · 28 July 2026 · 4 min
People ask what percentage of a portfolio should be in crypto. The useful version of the question is meaner. How many euros could this sleeve lose, quickly, while your job is stressful and the fund is also down, without forcing a sale or a new debt? That euro figure divided by a harsh but plausible crash is your maximum size. Percentages come second.
A crash of 50% is not a fantasy input for major coins. It is a planning input. If you cannot imagine typing it, you are not sizing. You are hoping.
Start from the loss, not from the boast
Write a euro amount you could see vanish and still pay rent, still fund the ETF, and still be someone your friends recognise. Call it L. Divide L by 0.5 if you want to survive a halving of the sleeve, or by 0.8 if you want room for something worse than a textbook bear market. The result is the most the sleeve should be worth on a calm day. If that number is €400, then €400 is the ceiling, even if a forum laughed.
Include the reward in the market value. A promotional credit is not outside the loss. If the sleeve is already near the ceiling because you deposited and also received crypto, stop. More buying is a future-you problem for a month when prices or contributions have changed the ratio.
Turn it into a percentage only after the euro figure exists
Now look at fund plus sleeve. If the ceiling is 4% and you are at 4%, you are done adding. If your euro ceiling is high because your finances are genuinely sturdy, the percentage might be larger. The order matters. Starting from “I want 20% because I am young” skips the only input that knows your rent.
Age is a weak proxy. A young reader with no buffer and a volatile contract job can afford less speculative inventory than an older reader with a paid-off flat and a pension already funded. Use the life you have. The buckets are how that life is organised.
Do not resize on the day the chart argues with you
Green weeks whisper that the ceiling was timid. Red weeks whisper that the whole sleeve was a mistake. Both whispers arrive when your judgment is worst. Change the ceiling on a review date you set in January, or not at all. If you must change it after a shock, write the reason in a sentence that does not contain the word “feel”.
Averaging down is not free bravery. It is a new, larger position. It counts against the ceiling. If the ceiling is already met, the brave and the disciplined act are the same: do nothing, or send the euros to the fund instead.
Small is a complete strategy
A first step of €50, including via the Robinhood EU referral, sits under almost every honest ceiling. If you use the link to sign up and deposit at least €50, you'll receive €50 worth of crypto as a reward. Even the combined exposure is still a lesson-sized line for many households. You are allowed to remain at lesson size for a year. No one serious will audit your percentage except you.
If lesson size is the most your sleep can carry, that is not a temporary embarrassment. That is the position. Stay there, contribute to the fund, and reread this page before any number in the note gets edited.