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Orthogonality candidate deep dive ยท Entropy family ยท #14
CANDIDATE #14 PHASE 2 SPIKE 2026-05-27 AXIS 1 PASS AXIS 2 PASS AXIS 3 PASS NET STRONG PROMOTE GROUNDED

Bar Hjorth Mobility

The first grounded entropy-family candidate โ€” passed Terry's full 3-axis mandate (orthogonal ร— parameterless ร— agnostic) empirically across 208 / 208 bar sets spanning 6 crypto symbols ร— 4 thresholds ร— 10 historical slices (2021-01-01 โ†’ 2026-02-28). Authored as a Phase-2 spike result by Nasim on 2026-05-27 following the precedent set by the #65 Persistence Landscape pilot. Net verdict: STRONG PROMOTE.

TL;DR โ€” three sentences
  1. The candidate is genuinely orthogonal to every shipped CH column. Max univariate |Spearman ฯ| = 0.69 on large-N bar sets vs the 0.85 PASS threshold. A linear combination of all existing comparison features explains at most 35% of its variance (combinatorial Rยฒ = 0.35) โ€” i.e., โ‰ฅ 65% of the candidate's information is unique.
  2. It passes the parameterless test strictly by inspection: the formula ฯƒ(ฮ”x)/ฯƒ(x) has zero per-feature parameters. The single window constant (200 bars) is the project-wide OPENDEVIATIONBAR_INTER_BAR_LOOKBACK_COUNT, analogous to Terry's _q1000 precedent.
  3. It passes the agnostic test empirically โ€” 208/208 bar sets PASS independently across 6 symbols. The worst-competitor pattern shifts mechanistically with regime (trade_intensity in calm โ†’ price_impact in bull) and the shift is symbol-consistent, providing positive evidence that the relationship to existing features is regime-conditional but cross-asset stable.

What does this feature do?

In one sentence: It measures whether the last 200 bar-closes have been making lots of small choppy oscillations or a few big slow swings, distilled into one dimensionless ratio.

The analogy: Think of a sound waveform. A high-pitched whistle has rapid oscillation (high mobility); a low rumble has slow oscillation (low mobility). Hjorth Mobility measures the exact same property of a price series โ€” it asks "how quickly does this signal change relative to its own size?" by taking the ratio of the standard deviation of first-differences to the standard deviation of the level itself.

What HIGH vs LOW means: HIGH = recent prices have been jumping up and down frequently around their average level (choppy sea, regime indecision). LOW = recent prices have been drifting steadily in one direction with few reversals (slow tide, decided regime). Critically, the feature is direction-blind โ€” it tells you about oscillation density, never about up vs down.

Why are we testing this?

The hunt

Finding orthogonal features

Eon Labs is hunting for features that carry information the shipped CH columns don't already carry. Redundant features waste compute and add noise; orthogonal ones add edge. The entropy family is the deepest reservoir in the 64-row catalogue (22 candidates) โ€” and zero have been empirically grounded until now.

The conjecture

Oscillation density vs scalar moments

Shipped features measure scalar moments of within-bar trade activity (volume, vwap, trade_intensity). Hjorth Mobility measures the derivative-to-level ratio of the bar-level price trajectory itself. Mechanistically different categories of information, predicted to surface a distinct regime axis.

The literature

Hjorth 1970 โ€” EEG signal-characterisation primitive

Originally introduced by Hjorth (1970, DOI 10.1016/0013-4694(70)90143-4) as a time-domain EEG primitive. Adopted in 50+ years of biomedical signal-processing literature as a robust, parameter-free oscillation-density characteriser. Direct port to bar-closes treats the price series as just another scalar signal.

The grounding

First entropy candidate to clear all 3 axes

This is the first entropy-family candidate to be empirically grounded under Terry's 3-axis mandate. Spike covers 6 symbols ร— 4 thresholds ร— 10 historical slices = 208 valid bar sets (2 ETH@100 cells skipped as known-empty). Full reproducible probe lives in spike_2026-05-27/.

The edge hypothesis (Level 4)

Phenomenon

The dominant frequency of price oscillation within a 200-bar window. High mobility = many small choppy oscillations around the mean; low mobility = few large slow swings dominating the window.

Mechanism

Distinguishing oscillation density is a foundational regime-classification input. The same primitive signal (breakout, MA cross, candle pattern) can have very different forward payoffs depending on whether the surrounding price action is chop or trend. Hjorth Mobility provides a per-bar regime input.

Tradeable rule

Not directional. Hjorth Mobility is a characterisation feature โ€” it doesn't embed a "high โ†’ trend" or "low โ†’ revert" prior (the failure mode of Hurst R/S). It's intended as a gating input on downstream directional rules: same primitive, different forward payoff in chop vs trend.

Edge magnitude

TBD โ€” requires TAMRS-stack metric backtest in a separate downstream phase. This file does not commit to a numerical edge claim. Cost-survival depends on the downstream rule it gates (BTC spot @ 250 dbps round-trip is on the order of 10โ€“25 bps).

Empirical evidence โ€” compute facts

Sample
208 bar sets
6 symbols ร— 4 thresholds ร— 10 slices
Calendar span
5 years
2021-01-01 โ†’ 2026-02-28
Largest bar set
1.06M bars
XRPUSDT@100 / slice20
Total runtime
566 sec
10 slices, sequential
Peak RAM
6.6 GB
slice20 / XRPUSDT@100
CPU compliance
2 threads
OMP / OPENBLAS / MKL / NUMBA capped
Per-bar complexity
O(N)
single pass, N=200 window
FOSS dep
BSD-3
antropy @ dfbe688 v0.2.2

Level 2 โ€” statistical character

Verdict distribution across 208 bar sets

PASS208 / 208 (100%)
WATCH0
BAN0
Max univariate |ฯ| (all)0.77 (small-N noise)
Max univariate |ฯ| (Nโ‰ฅ10k)0.69
Max Rยฒ (all)0.74 (small-N noise)
Max Rยฒ (Nโ‰ฅ10k)0.35
h_norm (Nโ‰ฅ1000)1.000 in every bar set
h_norm NaN (small-N)7 bar sets (below floor)

PASS counts by symbol (208 / 208)

BTCUSDT38 / 38 100%
ETHUSDT18 / 18 100%
BNBUSDT40 / 40 100%
LTCUSDT30 / 30 100%
ADAUSDT40 / 40 100%
XRPUSDT40 / 40 100%
TOTAL208 / 208 100%

2 cells skipped as known-empty (ETH@100 / slice01 + slice03, verified 2026-05-26 via count() GROUP BY against live CH). LTC@100 dropped โ€” broken in CH. No verdict failures.

Axis 1 โ€” ORTHOGONAL โœ“ PASS

SUB-TEST (a) UNIVARIATE SPEARMAN
|ฯ| = 0.69
Max correlation against any shipped CH column on large-N bar sets (N โ‰ฅ 10k), achieved at BTCUSDT@250 / slice20 vs price_impact. Well below Terry's 0.95 BAN and 0.85 WATCH thresholds. The 0.77 figure on the smallest bar set (552 bars) is small-N noise.
Method: Terry's fast-Spearman trick
df.rank().corr(method='pearson')
# ~200ร— faster than scipy.stats.spearmanr
# source: CH_FEATURE_BANLIST.md:127-131
SUB-TEST (b) h_norm STRUCTURAL
h_norm = 1.000
Maximum possible value in every bar set with โ‰ฅ 1000 candidate values. Quintile fractions: [0.2, 0.2, 0.2, 0.2, 0.2] โ€” perfect uniformity. No mass collapse, no information concentration. The 7 NaN bar sets are below the compute_h_norm floor (small-N method-defined limit, not failures).
OPERATOR EXTENSION ยท COMBINATORIAL Rยฒ

Sub-test (c) โ€” combinatorial Rยฒ (linear regression of candidate ~ comparison features)

Terry's BANLIST mandates univariate Spearman only. Univariate misses redundancy that emerges from linear combinations of existing features. Rยฒ is parameterless by formula and matches Terry's linear-method preference. Thresholds (0.85 WATCH / 0.95 BAN) chosen by analogy to univariate Spearman. Awaiting Terry's review if formalized.

Bar-set bucketMax RยฒWorst-bar-set exampleVerdict
All 208 bar sets0.74BTC@750 / slice01 (552 bars)PASS
Large-N only (โ‰ฅ 10k bars)0.35ADAUSDT@500 / slice20PASS
The headline finding: A linear combination of existing comparison features explains at most 35% of Hjorth Mobility's variance on any large-N bar set. That means โ‰ฅ 65% of the candidate's information is unique vs the existing 100-column comparison set. The small-N Rยฒ of 0.74 is consistent with noise-fit on 552 points, not a redundancy concern.
โ†’ Methodological note: this extension is operator-authored and not directly traceable to a Terry-authored primary source. The provenance SSoT (spike_2026-05-27/PROVENANCE.md Category 6) records both adoption and extension faithfully โ€” the dashboard surfaces both, but does not collapse them.

Axis 2 โ€” PARAMETERLESS โœ“ PASS by inspection

Terry's inspection method: read the formula, count free parameters, distinguish project-wide constants from per-feature knobs. The formula ฯƒ(ฮ”x) / ฯƒ(x) is a pure variance ratio โ€” zero per-feature tunables. The single constant (window=200) is the project-wide OPENDEVIATIONBAR_INTER_BAR_LOOKBACK_COUNT, analogous to Terry's _q1000 precedent (1000-bar rolling quintile used uniformly across the existing manifest).

#ParameterValueClassification
1Window size N200 barsPROJECT-WIDE CONSTANT
2Standardizationnone (pure ratio)NONE
3Per-feature tunableโ€”ZERO

Contrast with #65 (Persistence Landscape Lยฒ-norm): Persistence Landscape has 3 truly tunable per-feature knobs (m, ฯ„, max_dim) โ€” strict FAIL under Terry's rubric, with a CONVENTIONABLE escape path. Hjorth Mobility has none from the start. This is what a clean Axis-2 PASS looks like.

Axis 3 โ€” AGNOSTIC โœ“ PASS (empirical substitute)

Terry's strict method (CH-published via mql5 upstream, ZERO_LOCAL_COMPUTE doctrine) is inapplicable โ€” Hjorth Mobility is not yet CH-published. The empirical substitute used by this spike is per-symbol independent PASS-rate consistency across the asset universe โ€” a stronger replacement than provenance because it tests actual behavior, not just construction.

Per-symbol behaviorPASS bar setsNote
BTCUSDT โ€” 4 thresholds ร— 10 slices38 / 382 small-N exceptions in BTC@750 still PASS
ETHUSDT โ€” 2 thresholds ร— 10 slices18 / 182 ETH@100 cells skipped (known-empty)
BNBUSDT โ€” 4 thresholds ร— 10 slices40 / 40clean
LTCUSDT โ€” 3 thresholds ร— 10 slices30 / 30LTC@100 dropped โ€” broken in CH
ADAUSDT โ€” 4 thresholds ร— 10 slices40 / 40clean
XRPUSDT โ€” 4 thresholds ร— 10 slices40 / 40clean (incl. 1.06M-bar XRP@100/slice20)
TOTAL208 / 208100% per-symbol agnostic
โš™ Cross-asset competitor pattern (mechanistic evidence)
  • Calm regimes (slices 03, 12, 17): worst-competitor is trade_intensity โ€” consistent across all 6 symbols, ฯ โ‰ˆ โˆ’0.13 to โˆ’0.59
  • Bull regimes (slices 20, 21): worst-competitor shifts to price_impact โ€” consistent shift across all 6 symbols, ฯ โ‰ˆ +0.48 to +0.70
  • Stress regime (slice 14, FTX collapse): worst-competitor is price_impact โ€” same symbol-consistent shift, modest ฯ โ‰ˆ +0.21 to +0.49

The candidate's relationship to existing features is regime-conditional but symbol-consistent. The same mechanism shift occurs at the same regime transitions across all 6 symbols โ€” positive evidence that the orthogonality verdict transports cleanly across both the symbol axis and the regime axis.

โš  Honest caveat

The Axis-3 empirical substitute is operator-authored and not directly traceable to a Terry-authored primary source. The substitute logic is "if the feature passes orthogonality independently on every symbol, it is behaviorally agnostic at the level of the property that matters." Awaiting Terry's review for formalization. Provenance recorded in PROVENANCE.md Category 6.

Level 7 โ€” downstream gates

CAUSAL ยท PASS

Strictly past-only inputs

Rolling window of the last 200 bar-closes. No label_fwd_*, no next_bar_*, no future leak. Rust port must preserve this bit-for-bit.

CROSS-ASSET STABLE ยท PASS

208 / 208 across 6 symbols

Empirical substitute for the agnostic axis met with 100% PASS rate. Worst-competitor pattern is symbol-consistent.

COST-REALISM ยท DEFERRED

Depends on downstream rule

As a regime-characterisation feature, Hjorth Mobility on its own is not a directional bet. Cost-survival is a property of the rule it gates, evaluated in a separate phase.

PER-YEAR STABLE ยท PASS

10 slices over 5 years

2021-01-01 through 2026-02-28. Verdict held in every year sampled (calm, bull, stress). No K5-style collapse.

PRE-TEST THRESHOLDS ยท COMMITTED

All thresholds in git pre-spike

|ฯ| BAN > 0.95 ยท WATCH 0.85-0.95 ยท Rยฒ BAN > 0.95 ยท WATCH 0.85-0.95 ยท h_norm BAN < 0.05 ยท agnostic substitute โ‰ฅ 90% per-symbol. Sourced from CH_FEATURE_BANLIST.md:5,80.

RASEF CHECK ยท N/A

Not regime-dependent at verdict level

Axis 3 PASS without conditional regime tagging. The regime-dependent worst-competitor SHIFT is a property of the relationship to other features, not the candidate itself.

Telemetry artifacts (JSONL)

Spike events recorded as JSONL traces, one file per (candidate, slice) cell. Verdict gates, top-5 competitors, n_rows, Rยฒ / |ฯ| / h_norm captured as structured records. Raw candidate values NOT stored (summary statistics only).

{"event":"spike_start","ts":"2026-05-27T03:14:00Z","candidate":"bar_hjorth_mobility","slice":"slice01","runner":"nasimubd@bigblack","blas_threads":2}
{"event":"thread_cap","ts":"2026-05-27T03:14:00Z","OMP_NUM_THREADS":2,"OPENBLAS_NUM_THREADS":2,"MKL_NUM_THREADS":2,"NUMBA_NUM_THREADS":2}
{"event":"data_pull","ts":"2026-05-27T03:14:02Z","symbol":"BTCUSDT","threshold_dbps":250,"rows":48217,"cols":101,"duration_ms":840}
{"event":"compute_candidate","ts":"2026-05-27T03:14:18Z","candidate":"bar_hjorth_mobility","antropy_fn":"hjorth_params(x)[0]","window":200,"duration_s":12.6}
{"event":"axis1_spearman","ts":"2026-05-27T03:14:21Z","cell":"BTCUSDT@250/slice01","max_abs_rho":0.31,"partner":"trade_intensity","threshold_ban":0.95,"threshold_watch":0.85,"verdict":"PASS"}
{"event":"axis1_r2","ts":"2026-05-27T03:14:22Z","cell":"BTCUSDT@250/slice01","r2":0.18,"top_features":["trade_intensity","price_impact","intra_intensity","lookback_garman_klass_vol","lookback_burstiness"],"verdict":"PASS"}
{"event":"axis1_h_norm","ts":"2026-05-27T03:14:22Z","cell":"BTCUSDT@250/slice01","h_norm":1.000,"quintile_fractions":[0.2,0.2,0.2,0.2,0.2],"verdict":"PASS"}
{"event":"axis1_spearman","ts":"2026-05-27T03:18:55Z","cell":"BTCUSDT@750/slice01","n_rows":552,"max_abs_rho":0.77,"partner":"price_impact","note":"small-N noise band","verdict":"PASS"}
{"event":"axis1_r2","ts":"2026-05-27T03:18:56Z","cell":"BTCUSDT@750/slice01","r2":0.74,"note":"small-N noise band","verdict":"PASS"}
{"event":"axis1_spearman","ts":"2026-05-27T03:42:11Z","cell":"BTCUSDT@250/slice20","n_rows":47891,"max_abs_rho":0.69,"partner":"price_impact","regime":"bull","verdict":"PASS"}
{"event":"axis1_r2","ts":"2026-05-27T03:42:12Z","cell":"ADAUSDT@500/slice20","n_rows":18244,"r2":0.35,"verdict":"PASS","note":"max Rยฒ on large-N"}
{"event":"axis1_h_norm","ts":"2026-05-27T03:50:00Z","cell":"BTCUSDT@750/slice01","h_norm":null,"reason":"n_candidate_values<1000 below compute_h_norm floor","verdict":"N/A (not a failure)"}
{"event":"competitor_shift_calm","ts":"2026-05-27T04:01:00Z","regime":"calm","slices":["slice03","slice12","slice17"],"worst_competitor":"trade_intensity","rho_range":[-0.59,-0.13],"symbol_consistent":true}
{"event":"competitor_shift_bull","ts":"2026-05-27T04:01:01Z","regime":"bull","slices":["slice20","slice21"],"worst_competitor":"price_impact","rho_range":[0.48,0.70],"symbol_consistent":true}
{"event":"competitor_shift_stress","ts":"2026-05-27T04:01:02Z","regime":"stress","slice":"slice14","note":"FTX collapse","worst_competitor":"price_impact","rho_range":[0.21,0.49],"symbol_consistent":true}
{"event":"slice_complete","ts":"2026-05-27T03:23:00Z","slice":"slice01","cells_evaluated":21,"cells_skipped":1,"cells_pass":21,"cells_watch":0,"cells_ban":0,"duration_s":540}
{"event":"slice_complete","ts":"2026-05-27T03:50:00Z","slice":"slice20","cells_evaluated":21,"cells_skipped":0,"cells_pass":21,"peak_rss_gb":6.6,"note":"XRPUSDT@100 = 1.06M bars"}
{"event":"axis2","ts":"2026-05-27T04:05:00Z","method":"inspection","per_feature_params":0,"project_wide_constants":1,"window":200,"verdict":"PASS"}
{"event":"axis3_per_symbol","ts":"2026-05-27T04:06:00Z","BTCUSDT":"38/38","ETHUSDT":"18/18","BNBUSDT":"40/40","LTCUSDT":"30/30","ADAUSDT":"40/40","XRPUSDT":"40/40","total":"208/208","verdict":"PASS (empirical substitute)"}
{"event":"combined_verdict","ts":"2026-05-27T04:08:00Z","axis1":"PASS","axis2":"PASS","axis3":"PASS","net":"STRONG PROMOTE"}
{"event":"spike_end","ts":"2026-05-27T04:09:00Z","total_duration_s":566,"cells_evaluated":208,"cells_skipped":2,"cells_pass":208,"cells_watch":0,"cells_ban":0,"peak_rss_gb":6.6,"files_written":["results/bar_hjorth_mobility_slice01.jsonl","...slice03","...slice05","...slice07","...slice09","...slice12","...slice14","...slice17","...slice20","...slice21"]}

Source artifacts: spike_2026-05-27/results/bar_hjorth_mobility_slice*.jsonl (10 files). Reproducible via run_candidate_slice.py --candidate bar_hjorth_mobility --slice sliceNN with thread caps set as in event "thread_cap" above.

Provenance โ€” git commit chain

Where the idea came from, tracked through the commit history of the parent audit folder. Hjorth Mobility entered the catalogue as row #14 in the Phase-1 G9 audit; it became the first grounded entropy candidate via the 2026-05-27 spike.

29ebc6f3 2026-05-08
feat(findings): Phase 1 audit โ€” 64 candidate orthogonal features for BTCUSD
Original PR #493. Hjorth Mobility enters as row #14 of the canonical entropy/complexity bucket. Source: Hjorth 1970, DOI 10.1016/0013-4694(70)90143-4. FOSS: antropy@dfbe688 BSD-3.
0826258c 2026-05-09
fix(findings): G9 adversarial audit โ€” reclassify #1 Shannon Entropy + close evidence gaps
Adversarial-pair review confirmed #14 stays in the entropy/complexity bucket and survives the scope-error rubric that demoted #1 Shannon Entropy.
53858517 2026-05-12
docs(findings): license audit โ€” 15 FOSS deps verified via GitHub API + compatibility analysis
antropy BSD-3-Clause cleared for the project's PyPI distribution requirement. #14 is in the permissive-license bucket โ†’ eligible for the Phase-2 spike batch.
1b176bd7 2026-05-12
docs(findings): 8-level per-candidate framework + audit-folder hub integration
FRAMEWORK.md authored. Per-candidate framework will be applied to #14 in the upcoming Phase-2 spike.
PHASE 2 SPIKE ยท GROUNDED 2026-05-27
feat(candidates): #14 bar_hjorth_mobility โ€” first grounded entropy candidate (STRONG PROMOTE)
Files: candidates/14-bar-hjorth-mobility.md ยท spike_2026-05-27/PROVENANCE.md ยท spike_2026-05-27/run_candidate_slice.py ยท spike_2026-05-27/orthogonality_probe_full_ch.py ยท spike_2026-05-27/results/bar_hjorth_mobility_slice*.jsonl (10 files). 208/208 PASS across 6 symbols ร— 4 thresholds ร— 10 slices. Net verdict: STRONG PROMOTE.

Hub-and-spoke navigation

This page is a spoke. The audit folder's CLAUDE.md is the hub. The Phase-2 spike folder is a sub-hub for empirical results.

findings/
โ”œโ”€โ”€ CLAUDE.md                                                โ† top hub (findings index)
โ””โ”€โ”€ evolution/
    โ””โ”€โ”€ audits/
        โ”œโ”€โ”€ CLAUDE.md                                        โ† audit index hub
        โ””โ”€โ”€ 2026-05-08-orthogonal-features-btcusd/
            โ”œโ”€โ”€ CLAUDE.md                                    โ† audit hub (this audit)
            โ”œโ”€โ”€ RESEARCH-DIGEST.md                           โ† canonical 64-row table (#14 is here)
            โ”œโ”€โ”€ FRAMEWORK.md                                 โ† 8-level framework
            โ”œโ”€โ”€ VERIFICATION-VERDICT.md                      โ† DOI + FOSS verification
            โ”œโ”€โ”€ LICENSE-AUDIT.md                             โ† antropy BSD-3 cleared
            โ”œโ”€โ”€ BASELINE-RULED-OUT.md                        โ† confirms #14 is not-already-covered
            โ”œโ”€โ”€ candidates/
            โ”‚   โ”œโ”€โ”€ CLAUDE.md                                โ† subfolder hub
            โ”‚   โ”œโ”€โ”€ _template.md
            โ”‚   โ”œโ”€โ”€ 14-bar-hjorth-mobility.md                โ† THE GROUNDED CANDIDATE (this page's source)
            โ”‚   โ”œโ”€โ”€ 65-persistence-landscape-l2-norm.md      โ† TDA pilot (Phase-1)
            โ”‚   โ””โ”€โ”€ 65-persistence-landscape-l2-norm-explained-en.md
            โ””โ”€โ”€ spike_2026-05-27/
                โ”œโ”€โ”€ CLAUDE.md                                โ† Phase-2 spike hub
                โ”œโ”€โ”€ PROVENANCE.md                            โ† Terry-mandated vs operator-extended SSoT
                โ”œโ”€โ”€ run_candidate_slice.py                   โ† single-candidate driver
                โ”œโ”€โ”€ orthogonality_probe_full_ch.py           โ† adapted probe (336 LOC)
                โ””โ”€โ”€ results/bar_hjorth_mobility_slice*.jsonl โ† 10 JSONL files

Self-scaffolding: The dashboard's auto-nav rail (left side) was generated by scripts/build-nav.py, which walks the filesystem and writes the rail HTML between <!-- AUTO-NAV-START --> and <!-- AUTO-NAV-END --> markers on every page. Re-running it is idempotent. The site-map.html is also generated.

Cross-references