Position size is your real risk dial
Leverage feels like the risk control; it isn’t. Your risk is position size × stop distance. Fix your risk %, size to the stop, and you can’t blow up on one trade. See the streak math on the risk of ruin calculator.
The size ceiling your stop dictates
Maximum position size isn't what the exchange lets you buy — it's what your risk tolerance divides out to: max size = (account × risk %) ÷ stop distance %. A $10,000 account risking 1% with a 4% stop supports a $2,500 position. Not more, no matter how good the setup looks.
The formula's power is that leverage falls out of it naturally. That $2,500 position might be 0.25x of your account or 5x of a small margin allocation — the risk is identical because the stop distance and dollar loss are identical. Leverage decides margin efficiency, not risk. Sizing from leverage ("I always use 10x") instead of from the stop is the fundamental error behind most blowups.
Tighter stops permit bigger sizes — which is the seduction to resist. A 1% stop supports a $10,000 position under the same rules, but 1% is inside normal noise for most coins; you'll be stopped out by randomness. The stop must fit the market's wiggle first, and then the size follows.