Scaling in on pullbacks: how costs compound quietly

[Amanhasnoname]

Adding to a winner on a pullback looks efficient. The first entry proves the idea, the second joins at a better price, and the average improves. The trouble is in how the numbers stack.

Suppose each entry carries a 1 pip effective cost between spread and commission, and the target is 8 pips. A single entry spends 12 percent of the target on costs. Three entries with the same target spend that three times in absolute terms, while the later entries have smaller room to the target because price has already travelled. The third add might have a 4 pip target against the same 1 pip cost, which is 25 percent. The marginal return is getting worse as the position gets bigger.

Risk compounds in the other direction too. A single stop covering all three entries means total risk is roughly three times the first one unless the stop is tightened, and tightening it puts the stop inside normal pullback noise.

Scaling in works best when each add is sized smaller than the previous, and when the stop for the whole position is already at breakeven before the add. Anything else is closer to averaging into a trade that has not confirmed.

How do you size your adds relative to the first entry, and what happens to the stop when you add?