Pullback depth after London breakouts: 38% or deeper?

[FXS London Scalper]

After a breakout of the Asian range, many traders wait for a pullback before entering. How deep those pullbacks go, relative to the first impulse leg, deserves measuring on your own pair instead of assuming a Fibonacci level.

How to measure:

• Take breakouts that later reached at least 1.5 times the impulse length (the winners you'd want).
• For each, record the deepest pullback as a percentage of the impulse before continuation.
• Bucket them: under 30%, 30–60%, over 60%.

Why it matters, as a worked example: suppose a quarter pull back less than 30%, under half land in 30–60%, and the rest go deeper than 60%. Waiting for 50% would then miss roughly a third of the winners. Entering at 30% fills more often, but also fills more trades that keep going against you.

That spread is why a split entry is common: half size around 38%, second half at the breakout level if it's retested, with one stop under the whole structure.

Remember to also log the breakouts that failed. Measuring only winners tells you about fills, not about whether the entry level helps.

Has anyone measured this? I'd like to compare EURUSD with GBPUSD, which feels deeper on pullbacks.

[Amanhasnoname]

I measured this on GBPUSD over roughly a hundred and twenty London breakouts last winter, and your hunch matches what I found. The pound pulled back deeper than the euro as a rule. Only about one in five of my winners held above a 30% retrace, and a good chunk went past 60% before continuing, often wicking right back into the top of the Asian box first.

That changed how I enter. I stopped trying to catch the shallow pullbacks on GBPUSD altogether and now wait for price to come back near the broken range edge, then look for a one minute higher low there. I miss the fast runners, but the fills I do get have a much tighter stop because the structure is right underneath.

On EURUSD I left the split entry in place, roughly like you describe, because the pullbacks were tighter and more evenly spread. The point about logging failures is the important one. When I added them in, deep pullbacks past 70% were mostly failed breakouts, so I treat that depth as my exit signal now.