Position sizing from a risk budget

position_size = (equity * risk_pct) / (entry_price - stop_price)

Your stop-loss defines the worst-case loss per unit. Divide your risk budget by that to get the position size.

• Equity: $10,000
• Risk budget: 1.5% = $150
• Entry: $30,000 BTC
• Stop: $28,500 (5% below entry)
• Loss per BTC: $1,500

Position size = $150 / $1,500 = 0.1 BTC = $3,000 notional.

So a trader with $10K who sees a good BTC setup and wants to risk 1.5% takes only $3K of exposure, NOT their full $10K. This is why professional traders appear to "under-use" their capital — they're sizing by risk, not by capital availability.

Compute position size given inputs.