Model sizing
$750 per trade · 7.5% of balance
Based on 65% win rate, 2.42R reward:risk input, and 100 simulated trades. Estimated chance of a 50% drawdown: 0.4%.
This model estimate is also the default risk in the Trade size calculator, where your entry and stop determine the quantity for one trade. Simulation results depend on the inputs and are not a forecast.
Inputs
65.0% win rate · 2.42R after modeled costs
No resolved calls available. Using your manual estimates.
Trading cost assumptions
Default: 0.045% taker fee on entry and exit, plus a separate 0.03% slippage allowance per side. Fees use position quantity × each fill price. Position notional is stop-risk dollars ÷ stop distance; leverage changes margin, not that fee exposure. Funding is not modeled.
Maximum modeled probability of a 50% drawdown.
Risk setting
Simulation starts at $750 per trade, adjusted with your balance. 7.5% of starting balance · 0.16× Kelly.
Each trade is capped at the amount the current balance can cover, including the modeled loss-side costs.
Initial modeled loss including costs: $806. The per-trade sizer treats the shared risk percentage as an all-in budget, so its price-risk amount can be smaller.
Simulation settings
Your plan and Kelly, explained
Kelly is the inspiration for this tool: having an edge is only part of the problem; how much you risk affects how your balance compounds. The strategies below use the same win rate, reward:risk, and simulated win/loss sequences. Only the sizing rule changes.
Current assumptions: 65.0% wins, +2.42R on a win, −1.07R on a loss. Both winning and losing outcomes include entry and exit costs, based on each leg's notional. Amounts below are the planned stop risk, before any additional loss-side costs.
| Strategy | Initial risk setting | What it means |
|---|---|---|
| Your plan | 7.5% · $750 | The model's selected percentage, using your drawdown tolerance and simulation length. |
| Full Kelly | 46.1% · $4,606 | 100% of the calculated Kelly fraction of current balance. Targets maximum long-run expected log growth under the model. |
| Half Kelly | 23.0% · $2,303 | Half the full-Kelly percentage. Less exposure to each outcome, with lower theoretical growth. |
| Quarter Kelly | 11.5% · $1,152 | One quarter of the full-Kelly percentage. A further reduction in exposure and theoretical growth. |
Why not use full Kelly every time? It assumes your probabilities and payouts are correct and stable. It can produce large drawdowns even when those assumptions hold. Trading adds uncertain estimates, changing conditions, costs, and losses beyond a planned stop. Half and quarter Kelly reduce exposure to those errors and usually soften drawdowns; they do not remove the risk of losing money.
A Kelly fraction is a percentage of current balance to risk, not the percentage of trades you take or the size of a leveraged position. If the strategy has no positive expected edge after costs, changing the size cannot make its expected return positive.
Understand Kelly Criterion and try the game →Simulated outcomes
Sizing comparison
Net-payoff scenarios
Trade size calculator