Trading Profit and Loss: Gross vs Net, Fees and Break-Even

Long and short P&L

A long trade profits when price rises: (exit − entry) × quantity. A short trade profits when price falls: (entry − exit) × quantity. A short's maximum profit is capped (price can only fall to zero) while its potential loss is not — one of the reasons short positions need firm stops.

Every cost that turns gross into net

• Commissions and exchange fees, either fixed per order or a percentage of the trade's value, charged on both entry and exit.
• Spread, the gap between bid and ask. It is usually already reflected in your fill prices, so don't count it twice.
• Funding and swaps for perpetual futures and leveraged forex/CFD positions held over time.
• Borrow fees for short-selling stocks.

The profit & loss calculator separates all of these so you can see exactly how much each one costs.

How much do costs really matter?

Costs are fixed per trade while price moves vary, so they hurt most where moves are small. A round-trip cost of 0.2% is negligible on a swing trade targeting 15%, but it's a fifth of the profit on a scalp targeting 1%. In R terms: if your stop is 0.5% away and costs are 0.1%, every trade pays 0.2R before it starts. A strategy with +0.15R gross expectancy is losing money net.

The break-even price

Because costs are paid in both directions, every trade starts slightly underwater. The break-even exit price is where net P/L is exactly zero. On a long trade with percentage fees it sits a little above entry; on a short, a little below. Knowing it matters most when you move a stop to “break-even”: a stop placed exactly at entry still produces a small loss after costs.

Return on what?

Three different percentages are often confused:

• Price change — how far price moved.
• Return on position — net P/L ÷ position value. Includes costs.
• Return on account — net P/L ÷ account balance. This is what compounds and what you should compare with benchmarks.

A 20% return on a small position may be a 1% account return. A 2% price move on a 10× leveraged position is roughly a 20% account move — in either direction.