Scaling out on a 3-pip scalp makes no sense, here is my maths

[FXS London Scalper]

I see a lot of advice about scaling out of trades. For larger targets it can make sense. For my very short scalps, it doesn't, and the maths shows why.

Example on EURUSD: stop 4 pips, target 3 pips, round trip cost 0.7 pips. If I close half at 1.5 pips and the rest at 3:

• The first half earns 1.5 minus the cost, about 0.8 pips net on that half.
• The second half earns 2.3 pips net if it reaches the target.
• The cost per lot doesn't change when you split, so the 0.7 pips is paid on both halves anyway. Splitting saves nothing on costs and only lowers the size that reaches the full target.

The average win drops while the loss stays the same if the trade fails after the first partial, unless the stop moves. And moving the stop to breakeven after 1.5 pips on EURUSD is very tight, so many trades get stopped out at entry.

For me the conclusion is simple: on scalps under 5 pips I take the whole trade off at one target.

Do others agree, or have you found a way to make partials useful on very small targets?