LON BOTH BULL
London sweeps Asia low first, then reclaims and sweeps Asia high by 9:30 — a bull takeover pattern. Tight-Asia subset hits 64% UP close; with inside/below gap, 70%.
updated 2026-04-21The setup
London session sweeps both Asia extremes — but in a specific order:
- Asia low is taken out first (early manipulation to the downside)
- Price reverses, reclaims the Asia range, and then sweeps Asia high
This L→H ordering is the bull-takeover flag. The mirror pattern (H→L) is a bear takeover but shows no close-direction edge — we don’t trade it.
Entry rules
- Timing: 09:30 ET (RTH open) after the L→H order has been established
- Target: London high + 87 points (p50 excursion in this cohort)
- TTL: 390 minutes (through 16:00 ET)
Probability table:
| Asia width | Gap class (9:30 open vs Asia) | Probability |
|---|---|---|
| tight (<40pt) | inside or below | 70 |
| tight | normal | 65 |
| normal | inside or below | 65 |
| normal | normal | 58 |
| wide / xwide | any | skip |
Backtest
n = 1,364 MNQ sessions. Distribution of London sweep types:
| London sweep type | n | % | NY close UP | NY close DN |
|---|---|---|---|---|
| ONLY_H | 582 | 42.7% | 52.7% | 47.3% |
| ONLY_L | 466 | 34.2% | 53.0% | 47.0% |
| BOTH H→L (bear takeover) | 118 | 8.7% | 53.4% | 46.6% |
| BOTH L→H (bull takeover) | 115 | 8.4% | 58.3% | 41.7% |
| Neither | 83 | 6.1% | 54.2% | 45.8% |
Both-swept ≈ 17.1% of all sessions (consistent with Herman’s 18% observation). But only L→H prints a tradeable close-direction edge.
Sub-buckets that tighten the edge
| Filter | n | UP rate |
|---|---|---|
| + tight Asia (<40pt) | 65 | 64.6% |
| + INSIDE Asia gap | 20 | 70.0% |
| + BELOW Asia gap | 32 | 68.8% |
Excursion signature
The directionality shows up in the intraday excursion, not just the close:
- BOTH L→H: median +87pt past London high, only −31pt past London low
- BOTH H→L: median −98pt past London low, +34pt past London high
So the bear version actually has more intraday follow-through — but it doesn’t translate into close-direction edge. Only the bull version does. Another case of “touch ≠ close.”
Kill-switch interaction
Because L→H satisfies the “both Asia sides swept” condition, lon_both_swept=True also fires. The kill-switch would normally penalize this signal −10 prob. However, the L→H subset is the one carve-out where the both-swept pattern is productive — so the Python detection emits lon_both_active separately from the lon_both_swept chop flag, and the PredictionModel line for LON BOTH BULL is added from its own block, not from the chop-day branch.
Why Tier 2
The sample is thin (~19 fires/year) and the edge is modest (+5 to +12pt above baseline). Worth adding to the board, not worth sizing up on alone.
History
- 2026-04-21 — Shipped (Phase F). Built after the Herman 17-year Asia-London study led us to investigate both-swept patterns and we found the L→H asymmetry.