Inside-bar compression before Frankfurt opens: a test plan

[FXS London Scalper]

An inside bar on M5 just before 08:00 London, a candle whose high and low sit within the previous one, is sometimes treated as a coiled spring. A test plan before trusting it:

• Collect every M5 inside bar between 07:45 and 08:00 London on EURUSD and GBPUSD over at least a year.
• Record which side broke first after 08:00, how far price went in 30 minutes, and whether the first break reversed.
• Compare with a control: all M5 bars in the same window, inside or not.

The control decides it. If inside bars break with similar follow-through to ordinary bars, the pattern adds nothing beyond "the open moves".

Costs matter for the trade itself. An inside bar on M5 before the open is often only 3 to 5 pips tall, so a stop on the other side is tight and the spread at 08:00 can be a big share of it.

A practical variation: use the inside bar only as a reference level, and wait for a retest after the break rather than entering on the first tick.

Has anyone tested inside bars with a control group?