The mechanics study found the no-chase entry (buy the VWAP reclaim, not the breakout high)
was the dominant lever. This codifies it as a permanent, pre-registered shadow-validation —
the disciplined close-out of the 4-lever investigation arc.
- strategy/evaluation/vwap_pullback_entry.py: pure find_vwap_pullback_entry — first forward
bar that dips to the CUMULATIVE session VWAP (calculate_vwap, NOT the per-bar minute_bars.vwap
midpoint, which would make 'reclaim' trivially true) and closes back above it; entry = its
close, stop = its low (the tight no-chase structure stop). 4 tests.
- research/labeler.py validate_no_chase_entry + `validate-entry`: simulates it vs the ORB-high
breakout via the live simulate_exit on real forward bars, judged in PERCENT net of a REALISTIC
per-name cost proxy (4% sub-$3 / 2% else — no NBBO in bars). PRE-REGISTERED bar locked: mean
net% must be STRICTLY POSITIVE, 'less negative than ORB' is NOT a pass.
IN-SAMPLE RESULT (v1 gappers, 19 autocorrelated days): the no-chase entry HALVES the loss
(ORB -7.94% -> no-chase -3.61% net, median -4.23%, offered on 75%), robustly (day-jackknife
[-3.83%,-3.48%]) -- confirming not-chasing the spike-top is the strongest mechanic -- but it
still does NOT cross zero under realistic cost: PRE-REGISTERED BAR = FAIL. Consistent with the
whole arc: no mechanizable entry/exit/selection lever beats cost on the full gapper book; the
path to positive is FEWER/cleaner setups (cut the ~70% fader population) COMBINED with this
no-chase entry. validate-entry re-runs forward; promote only if it clears the bar out-of-sample.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
