A worked example shows why it matters. Suppose 300 trades on EURUSD and GBPUSD on a raw account:
- Gross result: +142 pips.
- Commission: −63 pips equivalent.
- Spread: −51 pips.
- Slippage: −19 pips.
- Net: +9 pips.
What the breakdown usually points to:
- Trade count is the multiplier. Marginal setups that break even gross become net losers.
- Pairs differ. A wider spread and more stop slippage can make one pair far more expensive than it looks.
- Session edges cost more. The first and last minutes of a session, while liquidity forms or leaves, tend to be the expensive ones.
- Very small targets rarely survive. Under 4 pips, cost is a large share of every win.