Check the strategy's Settings → Properties → Commission value and calculation mode. TradingView applies configured commission to entries and exits; slippage is a separate backtest cost.
What you may be seeing
- Commission paid is zero in Strategy Report
- Net P&L looks too high because trading fees are not being deducted
- Changing a broker fee assumption does not seem to affect the backtest
Most likely causes
- Commission is set to zero or the wrong calculation mode
- The Pine strategy declaration defines a different commission assumption
- Slippage is being confused with commission
Try this first
- Open the strategy settings and select Properties
- Find the Commission setting
- Choose the calculation mode that matches the fee model you want to simulate
- Enter the commission value
- Run the report again and inspect Commission paid and Net P&L
If that didn’t fix it
- Set commission_type and commission_value directly in the strategy() declaration when you control the Pine code
- Configure slippage separately when you also want to model execution-price friction
- Save the assumptions with your backtest notes so later comparisons use the same costs
Verify the fix
Strategy Report shows a non-zero Commission paid amount when the simulated trades and configured fee model should produce fees, and Net P&L reflects those costs.
Why this happens
TradingView only subtracts the commission model configured for the strategy. Open the strategy’s Settings → Properties and check the Commission setting, or define the corresponding commission parameters in the Pine strategy() declaration.
TradingView supports percentage, cash-per-contract, and cash-per-order commission models. Commission is applied to both entries and exits, and Strategy Report includes a Commission paid metric. Commission is separate from slippage, so realistic backtests may need both.