Spread and Commission Eat Scalpers Alive

[Fairman]

Here's a number every scalper needs to sit with for a moment: on a 5-10 pip profit target, a 1.5 pip spread already represents 15-30% of your entire target — gone before the trade has even had a chance to move in your favor.

This is the quiet math that separates scalping strategies that look good on paper from strategies that are actually profitable in live conditions. A backtest that ignores realistic spread and commission isn't testing your strategy. It's testing a fantasy version of your strategy that doesn't pay trading costs.

Before you commit real capital to any scalping approach, calculate your true breakeven win rate including costs — not the theoretical breakeven assuming a frictionless market. Include your actual broker's typical spread during your trading hours (spreads widen during low liquidity and news events, so use realistic, not best-case, numbers), plus any commission per lot.

Many traders discover, once they do this math honestly, that a strategy they assumed was solidly profitable is actually hovering right around breakeven once costs are properly subtracted. That's not a reason to give up on scalping — it's a reason to be selective about broker choice, trading sessions, and setup quality, because on tight timeframes, costs aren't a rounding error. They're a meaningful percentage of your edge.

[LondonScalper]

on a 5-10 pip profit target, a 1.5 pip spread already represents 15-30% of your entire target — gone before the trade has even had a chance to move in your favor.

This is the bit most strategy threads skip. A clean M1 pattern that needs 8 pips to work is often dead on a pair/session where all-in cost is 1.5–2 pips before you even breathe.

Practical filter I use: if typical spread+commission exceeds ~20–25% of the median M-target for that setup, the pair is demoted for that session — chart beauty notwithstanding. EURUSD London cash usually survives; thin crosses and early Asia gold often do not.

Backtests without realistic costs are entertainment. Live expectancy without a cost column in the journal is the same mistake wearing a different hat.

Which pairs are you finding still viable once you bake commission into the breakeven win rate?

[PropScalpDesk]

On a 5-10 pip profit target, a 1.5 pip spread already represents 15-30% of your entire target — gone before the trade has even had a chance to move in your favor.

That quiet math is why I stopped trusting frictionless backtests. True breakeven win rate includes realistic spread in my hours plus commission. Best-case website spreads are not the London-open tax I actually pay, and news widening is worse.

Selectivity follows: broker choice, session choice, and minimum target relative to cost. If costs need a hero win rate, the strategy is not “almost profitable” — it is unfinished. I also raise the bar on gold: absolute spread is larger, so R must clear a higher friction hurdle or the ticket stays theoretical.

Prop flavour: challenge accounts die from the same bleed, just faster when size is ego-driven. I micro-size until the cost sheet matches the plan.

What changed first when you did the honest breakeven math — pair shortlist, hold time, or broker?