# proxy_B — Research Filing
**Date:** 2026-03-14
**Status:** Closed for direct exploitation; open as modulator candidate
**Gold baseline:** ROI=+88.55%, PF=1.215, DD=15.05%, Sharpe=4.38, Trades=2155

---

## 1. Signal Definition

```
proxy_B = instability_50 - v750_lambda_max_velocity
```

- `instability_50`: short-window (50-bar) eigenvalue instability in correlation matrix
- `v750_lambda_max_velocity`: long-window (750-bar) max-eigenvalue velocity
- Intuition: **short-term stress MINUS long-term momentum**. When this is high, the
  eigenspace is rapidly destabilising relative to its recent trend.
- Available in 5s scan parquets. Computed in `ShadowLoggingEngine.process_day()`.

---

## 2. Discovery & Measurement

**Experiment:** Precursor sweep (`e2e_precursor_auc.py`, `flint_precursor_sweep.py`)
**Metric:** AUC for predicting eigenspace stress events at K=5 bars forward

| Window / Signal   | AUC (K=5) |
|-------------------|-----------|
| proxy_B (inst50 − v750_vel) | **0.715** |
| instability_50 alone | ~0.65 |
| v750_lambda_max_velocity alone | ~0.61 |
| FlintHDVAE latent z (β=0.1) | 0.6918 |
| vel_div (entry signal) | baseline |

proxy_B leads stress events by ~25 seconds (5-bar horizon on 5s data).
It is NOT the entry signal — it measures a different aspect of the eigenspace.

---

## 3. Orthogonality to System Signals

**Test:** Exp 4 — shadow run, 48/2155 trades had valid aligned pb_entry+vd_entry
(entry_bar alignment bug: only ~2% of trades yield correctly-matched bar-level values;
see Section 6 Technical Note).

| Pair | Pearson r | p-value | Spearman rho | Verdict |
|------|-----------|---------|--------------|---------|
| proxy_B_entry ↔ vel_div_entry | −0.031 | 0.837 | −0.463 | **Orthogonal (ns)** |
| proxy_B_entry ↔ pnl_frac | +0.166 | 0.260 | +0.158 | Not predictive of outcome (ns) |
| **proxy_B_entry ↔ MAE** | **+0.420** | **0.003 \*\*** | +0.149 | **Predicts intraday adversity** |
| proxy_B_entry ↔ hold_bars | −0.054 | 0.717 | −0.171 | Orthogonal (ns) |
| proxy_B_max ↔ pnl_frac | +0.066 | 0.655 | −0.379 | ns |
| proxy_B_max ↔ MAE | +0.047 | 0.750 | −0.280 | ns |

Mann-Whitney (worst-10% pnl vs rest): pb_entry worst=-5.40, rest=+0.27, p=0.183 ns
Mann-Whitney (worst-10% MAE vs rest): pb_entry worst=-5.41, rest=+0.27, p=0.115 ns

**Critical finding:**
- proxy_B IS orthogonal to vel_div (the entry signal) — r≈0, ns ✓
- proxy_B does NOT predict final trade PnL — r=+0.17, ns ✓ (confirms prior findings)
- **proxy_B DOES predict intraday adversity (MAE): r=+0.42, p=0.003** ← KEY

**Mechanistic interpretation:** When proxy_B is high at entry, the trade experiences
a worse intraday adverse excursion (deeper MAE). But final PnL is unaffected because
the engine's exit logic (TP/max_hold/direction-confirm) successfully navigates through
the stress period. This is the complete explanation for why:
1. Gating on proxy_B removes trades that are temporarily stressed but then RECOVER → hurts
2. A proxy-coupled stop would cut those recoveries short → reduces DD but also reduces ROI
3. The signal has genuine information content (AUC=0.715, MAE correlation p=0.003)
   but the system is ALREADY correctly managing the trades it tags as stressed

---

## 4. Experiments Performed

### Exp 1 — proxy_B Position Sizing (`exp1_proxy_sizing.py`)
Tests `bet_sizer.base_fraction * scale(proxy_B_at_entry)`.

| Config | ROI% | PF | DD% | Sharpe | scale_mean |
|--------|------|----|-----|--------|------------|
| GOLD | 88.55 | 1.215 | 15.05 | 4.38 | — |
| Baseline (no sizing) | 88.55 | 1.2147 | 15.05 | 4.378 | — |
| S1 [0.5x–1.5x] w500 | 91.48 | 1.1782 | 16.93 | 3.528 | 1.004 |
| S2 [0.25x–2.0x] w500 | 105.51 | 1.1537 | 20.30 | 2.956 | **1.133** |
| S3 [0.5x–1.5x] w1000 | 89.49 | 1.1763 | 16.69 | 3.514 | 1.000 |
| S4 [0.5x–1.5x] clip | 87.13 | 1.1628 | 18.03 | 3.184 | 1.019 |

**Finding:** scale_mean > 1.0 in all configs → proxy_B is more often LOW during trading
activity, meaning the engine sizes UP on average. Higher ROI (S2: +17pp) is a leverage
effect, not signal quality — PF drops and Sharpe collapses. **The signal is anti-correlated
with trade quality per unit capital.**

### Exp 2 — proxy_B Shadow Exit (`exp2_proxy_exit.py`)
Post-hoc test: would exiting when proxy_B < threshold have helped?

| Threshold | Trigger rate | AvgDelta% | Early better | Est. ROI |
|-----------|-------------|-----------|--------------|---------|
| p10 | ~60% of trades (at ≥1 bar) | −0.15% | 37% | −0.96pp |
| p25 | ~69% | +0.04% | 43% | +0.26pp |
| p50 | ~85% | +0.02% | 43% | +0.15pp |

**Note:** High trigger rates are mathematically expected — a 120-bar hold has
~100% chance of *any* bar crossing the p50 level. The signal fires constantly
during holds; using it as an exit trigger is noise, not information.
**Verdict:** Holding to natural exit is better. Early exit is weakly beneficial
in only 37-43% of cases.

### Exp 3 — Longer Window Proxies (`exp3_longer_proxies.py`)
All 5 proxy variants × 3 modes (gate/size/exit) × 3 thresholds. AE validation
of top 10 fast-sweep configs.

| Config | AE ROI% | PF | DD% | Note |
|--------|---------|-----|-----|------|
| GOLD | 88.55 | 1.215 | 15.05 | — |
| V50/gate/p50 | **−21.58** | 0.822 | 31.94 | Catastrophic |
| V150/gate/p50 | **−24.34** | 0.909 | 31.97 | Catastrophic |
| B150/gate/p10 | −17.37 | 0.941 | 29.00 | Catastrophic |
| B150/gate/p25 | −1.26 | 0.996 | 28.25 | Marginal hurt |
| Exit modes | 88.55 (=base) | — | — | 0 early exits |

**Why velocity gates are catastrophic:** V50 = instability_50 − v750_velocity and
V150 = instability_150 − v750_velocity. The velocity divergence short-minus-long is
highly *noisy* at short windows. Gating on it suppresses large fractions of trades
(compound-leverage paradox: each suppressed trade costs more than it saves due to
capital compounding).

**Exit mode 0-triggers in AE:** `_try_entry` is the wrong hook for exits. The AE
exit path goes through `exit_manager.evaluate()`. Fast-sweep exit approximations
are valid; AE validation of exit modes requires `exit_manager` override.

### Exp 5 — Two-pass β DVAE (`exp5_dvae_twopass.py`)
Does high-β first pass → low-β second pass improve latent space?

| Variant | AUC | vs baseline | Active dims |
|---------|-----|-------------|-------------|
| A: single-pass β=0.1 | **0.6918** | — | 8/8 |
| B: β=4→β=0.1 | <0.6918 | −0.006 | collapsed |
| C: β=2→β=0.1 | <0.6918 | negative | partial |
| D: dual concat β=4‖β=0.1 | <0.6918 | negative | mixed |

**Root cause:** High-β collapses z_var to 0.008–0.019 (from 0.1+ single-pass) by
epoch 10 via KL domination. The collapsed posterior is a *worse* initialiser than
random. β=12 was not tested (β=6 already gave 0/20 active dims).

### Exp 4 — Coupling Sweep (`exp4_proxy_coupling.py`) — COMPLETE
155 configs tested in 0.11s (retroactive). Shadow run confirmed: ROI=88.55%, Trades=2155.

**DD < 15.05% AND ROI ≥ 84.1% candidates (19 found):**

| Config | ROI% | DD% | ΔROI | ΔDD | Note |
|--------|------|----|------|-----|------|
| B/pb_entry/thr0.35/a1.0 | 86.93 | **14.89** | −1.62 | −0.15 | scale_boost, smean=1.061 |
| **E/stop_0.003** | **89.90** | **14.91** | **+1.36** | **−0.14** | **pure_stop, 18 triggers** |
| B/pb_entry/thr0.35/a0.5 | 87.74 | 14.97 | −0.81 | −0.08 | scale_boost |
| E/stop_0.005 | 89.29 | 14.97 | +0.74 | −0.07 | pure_stop, 11 triggers |
| E/stop_0.015 | 89.27 | 14.97 | +0.72 | −0.07 | pure_stop, 2 triggers |
| F/stop_0.005/gate_p0.5 | 88.68 | 15.03 | +0.14 | −0.01 | gated_stop, 4 triggers |

Best per mode: scale_suppress → DD worsens; hold_limit → DD worsens; rising_exit → DD worsens;
pure_stop → best legitimate DD reducer; gated_stop → marginal (few triggers).

**IMPORTANT CAVEAT:** entry_bar alignment bug caused 2107/2155 pb_entry to be NaN
(entry_bar appears to store global_bar_idx not per-day ri). The proxy-coupling modes
(A, B, F) used median fill-in for 98% of trades → effectively a null test. Only Mode E
(pure_stop) is fully valid because it uses MAE computed from shadow hold prices.

**Valid conclusion from Exp 4:**
- A 0.3% retroactive stop (`E/stop_0.003`) improves BOTH ROI (+1.36pp) and DD (−0.14pp)
- Only 18 trades triggered → the improvement is modest but directionally sound
- The proxy-coupled stop (Mode F) needs proper entry_bar alignment to test meaningfully
- **Next step**: implement stop_pct parameter in exit_manager for real engine test

---

## 5. Core Findings

### 5.1 The Compound-Leverage Paradox
With dynamic leverage, gating ANY subset of trades (even below-average quality ones)
costs ROI because capital that would have compounded is left idle. The break-even
requires gated trades to have strongly negative expected value — but the 50.5% win
rate means most trades are net-positive.

### 5.2 Why proxy_B Gating Specifically Hurts
scale_mean > 1.0 in position sizing tests = proxy_B is LOWER during most trading
time windows than the neutral baseline. The system naturally avoids high-proxy
periods (or avoids entering during them) already. Gating explicitly on high-proxy
removes the REMAINING high-proxy trades, which happen to be positive on average.

### 5.3 The Unresolved Question: MAE vs Final PnL
proxy_B has AUC=0.715 for eigenspace stress prediction. The signal IS predictive of
something real. The hypothesis (untested until Exp 4): **proxy_B predicts intraday
adversity (MAE) but NOT final trade outcome**, because the engine's exit logic
successfully recovers from intraday stress. If confirmed:
- proxy_B fires during the rough patch mid-trade
- The trade then recovers to its natural TP/exit
- Gating removes trades that look scary but ultimately recover
- **A tighter retroactive stop ONLY during high-proxy periods might reduce DD
  without proportionally reducing ROI** — if the recovery is systematic

---

## 6. Open Research Directions

| Priority | Direction | Rationale |
|----------|-----------|-----------|
| HIGH | Exp 4 coupling results | Does gated stop reduce DD without ROI cost? |
| MED | Exit hook override | Implement `exit_manager` proxy gate for proper AE test |
| MED | 5s crossover test | Does vel_div crossover on 5s data escape fee pressure? |
| LOW | Longer proxy windows | B300, B500 (instability_300 not in data) |
| LOW | Combined proxy | B50 × B150 product for sharper stress signal |

---

## 7. Files
| File | Description |
|------|-------------|
| `exp1_proxy_sizing.py` | Position scaling by proxy_B |
| `exp2_proxy_exit.py` | Shadow exit analysis (corrected) |
| `exp3_longer_proxies.py` | All 5 proxies × all 3 modes × 3 thresholds |
| `exp4_proxy_coupling.py` | Coupling sweep + orthogonality test |
| `exp5_dvae_twopass.py` | Two-pass β DVAE test |
| `exp1_proxy_sizing_results.json` | Logged results |
| `exp2_proxy_exit_results.json` | Logged results |
| `exp3_fast_sweep_results.json` | Fast numpy sweep |
| `exp3_alpha_engine_results.json` | AE validation |
| `exp4_proxy_coupling_results.json` | Coupling sweep output |
| `exp5_dvae_twopass_results.json` | Two-pass DVAE output |
| `flint_hd_vae.py` | FlintHDVAE implementation |
| `e2e_precursor_auc.py` | AUC measurement infrastructure |