What the study supports
LF/HF sequencing may materially influence later directional expansion probabilities. It is most useful as an expansion-regime classifier.
A pure conditional-probability classification model evaluating whether early-session high/low sequencing contains information about later intraday expansion. This is not an execution system and does not define entries, exits, stops, targets, or position sizing.
P(post-10:10 formation high break | LF), sample N = 578.
The 09:30–10:10 LF/HF framework measures whether the order of early-session high and low formation changes the later intraday probability distribution. LF sessions showed elevated upside expansion probabilities, while HF sessions showed elevated downside expansion probabilities. The strongest asymmetry appeared in post-formation directional extension rather than terminal close location.
| State | Definition | Interpretation |
|---|---|---|
| LF | First occurrence of the 09:30–10:10 low occurs before the first occurrence of the 09:30–10:10 high. | Low forms first; upside expansion state. |
| HF | First occurrence of the 09:30–10:10 high occurs before the first occurrence of the 09:30–10:10 low. | High forms first; downside expansion state. |
| SAME_BAR | Both first extremes occur on the same row/bar. | Ambiguous sequencing; separated from LF/HF. |
| Condition | Outcome | Sample Size | Probability |
|---|---|---|---|
| LF | Post-10:10 formation high break | 578 | 83.39% |
| LF | Post-10:30 IB high break | 578 | 74.91% |
| LF | Close above IB midpoint | 578 | 65.22% |
| HF | Post-10:10 formation low break | 577 | 79.38% |
| HF | Post-10:30 IB low break | 577 | 69.15% |
| HF | Close below IB midpoint | 577 | 54.94% |
Two sessions may print identical highs, lows, and ranges while forming those extremes in different orders. This framework isolates whether that sequencing itself contains conditional information. The model intentionally excludes quartile filters, prior-day location filters, VWAP filters, overnight inventory filters, volatility regime filters, and macro-event filters to preserve a cleaner base-rate framework.
LF/HF sequencing may materially influence later directional expansion probabilities. It is most useful as an expansion-regime classifier.
The framework does not establish a standalone trading edge, optimal execution, or future persistence. Rolling and out-of-sample validation are still required.
Use as an intraday regime label that informs risk expectations after the 09:30–10:10 formation window.
Test conditional behavior by volatility regime, prior-day location, IB range size, and rolling stability without contaminating the no-quartile base model.