The three position sizes
Assume a maximum 100 USDT loss before costs. At a 1% stop the notional is 100 ÷ 1% = 10,000 USDT; at 3% it is about 3,333.33 USDT; at 5% it is 2,000 USDT.
Each carries a theoretical 100 USDT price loss. The question is not which stop is inherently safer, but what room the strategy requires and what size matches that room.
Deduct fees and slippage first
Where costs enter the formula is easy to get wrong. They are added to per-unit risk, not deducted once from the budget: per-unit risk = stop distance + entry price × (round-trip fee rate + slippage rate). At teaching values of 0.10% round-trip and 0.10% slippage, that is an extra 0.20% of entry price per unit.
On the same 100 USDT budget, the notionals for a 1%, 3% and 5% stop move from 10,000, 3,333.33 and 2,000 to 8,333.33, 3,125.00 and 1,923.08 USDT. All three reproduce directly in the position size calculator.
In volatile or thin conditions a stop can fill through its price. The risk budget should carry a stressed slippage input rather than treating the stop price as a guaranteed fill.
The three stop distances in full
One 100 USDT risk budget, three stop distances side by side. Every row reproduces in the position size calculator.
The 1% stop loses 16.7% of its size. The 5% stop loses 3.8%.
Positions do not shrink proportionally once costs are included, because the fixed 0.20% is a larger share of a tight stop. The nearer the stop, the more fees weigh in the per-unit risk.
Notional = risk budget / (stop distance + round-trip fee rate + slippage rate)| Stop distance | Notional before costs | Notional with 0.20% costs | Reduction |
|---|---|---|---|
| 1% | 10,000.00 USDT | 8,333.33 USDT | −16.7% |
| 3% | 3,333.33 USDT | 3,125.00 USDT | −6.3% |
| 5% | 2,000.00 USDT | 1,923.08 USDT | −3.8% |
The last step: confirm liquidation sits beyond the stop
One check remains after sizing: where the liquidation level falls at the leverage you chose. If liquidation is nearer than the stop, the stop never triggers, and the real maximum loss is the margin rather than the risk budget.
Take the 3% stop with a 3,125 USDT notional. At r = 0.0055 the highest leverage that still leaves 3% of room is about 29×. At 10× the adverse distance is roughly 9.5%, comfortably beyond the stop. At 50× it is 1.46%, and liquidation arrives first.
The complete order is four steps: define the invalidation price, derive the stop distance, size from the risk budget, then check that leverage keeps the liquidation distance larger than the stop distance. Skip the fourth and the first three provide no protection.
- Let the strategy set the stop; do not reverse-engineer a stop from the leverage you wanted.
- Size equals risk budget divided by stop distance plus fees plus slippage.
- Leverage only changes margin and liquidation distance; it is not a second multiplier on size.
- Liquidation distance must exceed stop distance with room for mark price and spread.
Apply leverage after sizing
After finding notional, leverage estimates initial margin. A 3,333 USDT position needs roughly 667 USDT at 5x or 333 USDT at 10x.
The strategy loss budget remains 100 USDT. Higher leverage only reduces posted margin and the liquidation buffer; do not multiply notional again.
Practical workflow
Define strategy invalidation on the chart, calculate stop percentage, choose account risk, subtract cost allowances, then calculate notional. Finally confirm that the liquidation boundary sits beyond the stop.
Round quantity down when venue minimums or step sizes prevent an exact match, then recheck the order preview.
Official sources and calculation boundary
The liquidation ordering follows OKX's documentation; the sizing formula itself is venue-independent arithmetic on a risk budget. What does need checking with the venue is minimum size, size step and your account's maintenance tier.
Next checks in this series
Liquidation and margin risk
BTC at 5x, 10x, 20x and 50x: how liquidation risk changes
Reproducible scenario guide
Liquidation and margin risk
How adding margin changes a BTC long liquidation estimate
Reproducible scenario guide
Liquidation and margin risk
Why DZPTO, Binance and OKX can show different liquidation prices
Reproducible scenario guide
Frequently asked questions
Can a very tight stop support unlimited position size?
No. Tight stops are sensitive to noise and slippage and remain constrained by leverage, brackets, liquidity and available margin.
Should risk use account balance or available balance?
Use a consistent policy. Capital that is actually available and acceptable to lose is more conservative when other positions consume funds.
Why do tight stops suffer more from costs?
Because costs are a fixed percentage of entry price while the stop distance varies. A 0.20% cost is one fifth of a 1% stop but only one twenty-fifth of a 5% stop. The nearer the stop, the larger the share of per-unit risk that belongs to costs rather than price.
Should the risk budget come from total equity or available balance?
From the capital you are willing to lose on this strategy, which is usually less than total equity. If several correlated positions are open at once, account for them failing together: setting each to 1% of total equity means taking several times that risk when the positions move as one.