What fees do to a backtest
A futures fee is a percent of notional on each fill. A 10,000 notional round trip at 0.05 percent taker costs 10, and that cost can erase a 40 point gain.
A backtest fee is taken from notional, not from the cash you posted and not from the profit column. On a USD-margined perpetual, Binance writes the trading fee as position value times the fee rate, and position value as contract size times the execution price. The same fill that looks like a 40 dollar gain can owe 10 dollars in taker cost if both sides are charged.
The base is notional
Binance's futures fee FAQ, updated 1 May 2026, gives the USD-margined formula as trading fee equals position value times the trading fee rate, and position value equals contract size times execution price. Maker and taker rates vary by VIP level. The FAQ's regular-user example uses 0.02% for a maker fill and 0.05% for a taker fill. Those example rates are not a promise that your account pays them.
A taker fill is an order that executes against the book. Binance says a market order is always a taker fill. A maker fill rests first. The rate is smaller on the example maker side, but the base is still notional.
Leverage does not shrink that base. If the position is worth 10,000, the fee is a percent of 10,000. Posting 1,000 against that position does not cut the fee to a percent of 1,000.
One gain, two fills
These figures are a worked example, not a recorded run. One long is opened and closed on a notional of 10,000. The price move makes 40 before costs. Both fills use the FAQ's 0.05% taker example, so each fill costs 5.00.
fee = notional x rate
10,000 x 0.0005 = 5.00 per fill
The panel shows that net of +40 beside a net of +30. The price move did not change. The two fills did. A smaller gain than 10 would have printed as a loss after the same fees. Why win rate is not enough is the same warning from the other side: a high share of winners can still lose after payoff and cost.
What Tradee charges, and what it stores
Tradee stores the backtest commission as a percent of notional. A value of 0.05 means 0.05 percent, the same 0.0005 used above. The engine applies that rate on every fill, and every current engine fill is treated as a taker fill. Entry commission is taken when the position opens. Exit commission is taken when it closes. Both reduce the stored trade result.
Paper trading vs backtesting already separates the two tests. Paper fills in Tradee are stored at the reference price with zero commission and zero slippage, so a paper row is not a venue bill. Execution can show an overlay that estimates those costs for viewing. The stored paper trades stay raw. If you compare a paper book to a backtest, set the same rate on the historical run or you are comparing two cost models.
A backtest can also apply slippage as a percent of ATR. That is a second disadvantage on the fill price. This page is only the commission line. Funding between longs and shorts is a third cost, and who pays perpetual funding is the page for that payment.
This article is for education. It is not financial advice. Trading can lose money. Past results do not guarantee future results.