The block fed exactly one number: (v[i] - v[i-1]) / v[i-1]. That is the first difference,
and it cannot express three things that matter - the LEVEL relative to a baseline (two
dead bars and two frantic bars both read ~0 change), and the two volume-vs-range
interactions, where heavy participation that went NOWHERE (absorption) and heavy
participation that travelled (continuation) mean opposite things and currently collapse
onto the same value.
research/test_volume.py measures each candidate's mutual information with the triple-
barrier label across 3 instruments x 2 geometries, against a BLOCK-permutation null -
blocks sized to the barrier horizon, because adjacent labels share almost their entire
outcome window and a free shuffle yields a null so tight that everything looks
significant. Finite-sample MI bias (~7/n here) is reported alongside rather than
subtracted, since the permutation null already absorbs it.
Result: volLevel beats the shipped change ratio outright on 4 of 6 cells (EURUSD 2:3
+0.000118 excess at p=0.006, USDJPY 1:2 +0.000284 at p=0.002); absorption is the single
strongest reading anywhere in the sweep at EURUSD 1:2 (+0.000404, p=0.002) though it is
null on XAUUSD; vol x range clears on 4 of 6. The shipped change ratio is itself
significant on 5 of 6, so it stays.
Kept OUT: a session-relative z-score against the same hour-of-day's own recent history.
It was the weakest candidate - null on both EURUSD cells - and it is the only one needing
per-hour rolling bookkeeping in MQL5. Not worth the state for a reading that did not
survive its own null on the primary instrument.
Magnitudes, stated plainly because they are the point: the excess MI is ~2e-4 nats against
a label entropy near 1.05. That is under a tenth of one percent of the label's
uncertainty. It is real, it repeats across instruments, and it is nowhere near an edge -
this is worth having because it costs one 50-bar loop, not because it changes the answer.
Prior work stands: the whole single-series feature family measured at the noise floor.
m_neuronsCount is already in the fingerprint, so the width change re-keys existing caches
by itself, which is correct - the input vector genuinely changed shape.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
