# Sector-residual momentum (Tier-1 alpha research)

**Status:** **PROMOTE (to human design decision only)** — IC + A/B bars cleared; **do not ship**.  
**Branch:** `research/sector-residual-momentum`  
**Production impact:** none. Local research only. No scheduler / gate / prod-config changes.  
**Artifacts:** `reports/sector-residual-20260719-083356.json` (+ companion `.md`)

---

## Pre-registration (locked before first research run)

### Hypothesis

Residualizing 12–1 momentum against the sector, not only the market, reduces
factor volatility at similar return (Blitz / Huij / Martens-style) → higher
Sharpe on the production book when the residual replaces market-only residual
as the momentum leg.

### Signals (candidates)

| signal | construction |
|---|---|
| `mom_12_1_sector_resid` | Two-factor residual vs SPY + ticker’s sector ETF. Same window as `mom_12_1_resid`: ≥100 daily obs, 252-bar lookback, 21-bar skip; two-factor OLS betas **without intercept**; cumulate residual returns over the formation window. |
| `mom_12_1_sector_demeaned` | Plain `mom_12_1` minus the **cross-sectional** mean of `mom_12_1` within the same GICS sector that week (≥2 names in sector). No regression. |

### Baselines (same run, same cross-sections — iron rule)

Always report side-by-side with:

- `mom_12_1`
- `mom_12_1_resid`

Computed on the **identical** weekly non-overlapping cross-sections in this run.
Never compare against IC numbers from another report.

### Iron rule (IC harness)

Source of truth: `_signal_evaluation` in `app/services/backtest_service.py`.

- Mean weekly Spearman IC on **non-overlapping** weekly windows  
- Bar: \|mean IC\| ≥ ~0.03, **consistent positive sign**, `reliable: true` (≥ 12 windows)

### Promotion to portfolio A/B (candidate → book)

A candidate promotes to A/B **only if**:

1. It clears the iron-rule bar **and**
2. Its IC **t-stat ≥** that of `mom_12_1_resid` on the same cross-sections.

### Portfolio A/B grading (if and only if IC promotion fires)

- Swap candidate in as the **momentum leg** of the production 80/20 momentum/vol
  rank **and** as the gate-percentile signal.
- `fill_mode=close`, `COST_PER_SIDE = 0.001`, full config otherwise unchanged.
- Validation window = entries ≥ **2024-07-01** (call it **validation**, not
  holdout — contaminated by prior experiments).
- Pre-registered promotion bar:
  - validation Sharpe ≥ control − 0.5·SE  
  - full-period Sharpe and max-DD **not worse** than control  
- Report Lo / Mertens-adjusted SEs.

### Optional sector-cap sub-experiment

Only if labels are in **and** A/B ran: max **3** positions per sector in the
10-slot book. Same A/B grading. **Tail-trim presumption of guilt** (rule 4):
report entry counts and both tails of the R distribution. Rising win rate with
falling Sharpe/CAGR = red flag → do not promote.

**This run:** sector-cap arm **not executed** (optional; A/B unconstrained book
only). Can be a human-approved follow-up.

### Verdict labels

| label | meaning |
|---|---|
| **PROMOTE** | Clears pre-registered bar; human decides next (wire design separate) |
| **PARK** | Inconclusive / weak; keep machinery, no book change |
| **DEAD** | Failed iron rule or worse than residual baseline with clear sign |

### Explicit non-goals

- No production deploy from this doc  
- Do not resurrect: take-profit exits, EV gate, regime entry-blocking,
  inverse-vol sizing, gap-caps, unconditional FIP filter

---

## Data provenance

### Snapshot race guard

| check | result |
|---|---|
| Snapshot path | `backtest_snapshots/prod.sqlite` |
| Manifest | none (expected for prod snapshot); bar-count sanity applied |
| Tickers / OHLCV | **506** / **629,263** |
| Bars min / avg / max | 14 / 1246.1 / 1261 |
| OHLCV range | 2021-06-24 → 2026-07-02 |
| Partial-build red flags | none (avg bars healthy) |

Integrity fingerprint on same run: `fip_id` mean IC **−0.045** / t **−2.91**
(35 weeks, N≈498) — matches the established prod fingerprint.

### Sector labels

| source | count |
|---|---:|
| Public S&P 500 GICS CSV | 496 newly filled |
| FMP profile requests | 10 (all missing after CSV) |
| Mapped / universe | **505 / 506 (99.8%)** |
| With mappable ETF | 505 |
| Still missing | **RHM** only |

Persist path: `data/research/ticker_sector_map.json`.

FMP aliases (`Technology`, `Consumer Defensive`, `Financial Services`) map to
SPDRs via the alias table in `app/services/sector_map.py`.

### Sector ETFs in `benchmark_prices` (auxiliary only — not tradable)

| symbol | bars | min date | max date |
|---|---:|---|---|
| SPY | 1516 | 2020-07-06 | 2026-07-17 |
| XLB…XLY (11) | 1512 each | 2020-07-10 | 2026-07-17 |

Fetched via Alpaca `Adjustment.SPLIT` into **`benchmark_prices`** (same table as
SPY) so they never enter the ticker universe or candidate replay.

---

## Results

Generated: `2026-07-19T08:33:56`

### IC harness (identical cross-sections, production 506-name universe)

| signal | mean_ic | ic_t_stat | weeks | avg_N | reliable | ic+_pct | quintile spread |
|---|---:|---:|---:|---:|---|---:|---:|
| **mom_12_1_sector_resid** | **0.0578** | **2.34** | 35 | 497.7 | true | 65.7 | 0.0245 |
| mom_12_1_resid | 0.0552 | 1.98 | 35 | 497.7 | true | 60.0 | 0.0207 |
| mom_12_1 | 0.0531 | 1.61 | 35 | 497.7 | true | 65.7 | 0.0206 |
| mom_12_1_sector_demeaned | 0.0340 | 1.32 | 35 | 496.7 | true | 62.9 | 0.0154 |

### IC promotion grades

| candidate | iron rule | t ≥ resid | promote_to_ab |
|---|---|---|---|
| `mom_12_1_sector_resid` | pass (IC 0.058, +sign, reliable) | **yes** (2.34 ≥ 1.98) | **yes** |
| `mom_12_1_sector_demeaned` | pass (IC 0.034, +sign, reliable) | **no** (1.32 < 1.98) | **no** |

### Portfolio A/B — `mom_12_1_sector_resid` as residual leg

Config: production 80/20 residual/high-vol rank + gate percentile, `fill_mode=close`,
cost 10 bps/side, ATR trail / gate-reset re-entry as live. Validation split
2024-07-01.

| window | arm | Sharpe | Sharpe SE (Mertens) | CAGR % | max DD % | trades | n_days |
|---|---|---:|---:|---:|---:|---:|---:|
| train | control (resid) | 1.30 | 0.685 | 29.2 | 21.4 | 176 | 525 |
| train | treatment (sector resid) | **1.57** | 0.677 | **35.5** | **19.8** | 176 | 530 |
| validation | control | **2.92** | 0.709 | **76.3** | **11.7** | 150 | 501 |
| validation | treatment | 2.57 | 0.701 | 66.3 | 14.8 | 163 | 501 |
| full | control | 2.09 | 0.497 | 51.6 | 21.4 | 322 | 1000 |
| full | treatment | 2.09 | 0.491 | 51.0 | **19.8** | 337 | 1005 |

**Pre-registered A/B checks**

| check | result |
|---|---|
| val Sharpe ≥ control − 0.5·SE | **pass** (2.57 ≥ 2.92 − 0.5×0.701 = 2.5695) — **knife-edge** |
| full Sharpe not worse | **pass** (2.09 = 2.09) |
| full max DD not worse | **pass** (19.8 < 21.4) |

Qualified long candidates: control 1086 vs treatment 1210 (sector residual
gates a slightly larger set).

---

## Verdict

| signal | verdict | note |
|---|---|---|
| **`mom_12_1_sector_resid`** | **PROMOTE → human wire-in decision** | IC modestly beats market residual; A/B clears pre-reg bar narrowly. **Do not ship from this branch.** |
| **`mom_12_1_sector_demeaned`** | **DEAD** (for promotion) | Iron-rule IC magnitude ok, but t-stat loses to `mom_12_1_resid`. Cheap variant not competitive. |

### Read carefully (for the human)

1. **IC edge is real but small.** Sector residual IC 0.0578 / t 2.34 vs market
   residual 0.0552 / t 1.98 on the **same** 35 windows — better consistency
   (ic+ 65.7% vs 60%) and slightly higher mean, not a different factor class.
2. **A/B is not a clear Sharpe win.** Full-period Sharpe is flat (2.09).
   Validation Sharpe is **lower** than control (2.57 vs 2.92) and only clears
   the pre-registered “within 0.5 SE” cushion by ~0.001. Train improves;
   validation worsens — classic regime-split noise on ~2 years.
3. **Risk side is friendly.** Full max DD improves (19.8% vs 21.4%); train DD
   also better. Matches the “lower factor vol” half of the hypothesis more than
   the “higher Sharpe” half on this window.
4. **Survivorship / short history.** Same caveats as all current research:
   today’s constituents, ~35 independent weekly windows, one post-2021 regime
   dominant. Task 3 (history depth) should re-check IC stability before any
   wire-in.
5. **Not shipped.** Machinery lives on the research branch; production residual
   path is untouched.

---

## What a human must decide next

1. **Accept or reject** replacing `mom_12_1_resid` with `mom_12_1_sector_resid`
   as the production residual (gate + 80/20 mom leg), **or** keep market residual
   and treat sector residual as research-only.
2. If leaning accept: require **Task 3 history-depth** confirmation (IC era split
   pre/post-2021) before any production PR.
3. Optional: run **sector-cap ≤3** A/B with full tail diagnostics (not run here).
4. **Do not** merge this verdict into main strategy docs without review.
5. Wire-in design (live sector map refresh, ETF series ops, fallback when sector
   missing) is a **separate** approved engineering step.

---

## Implementation notes (research machinery)

| piece | role |
|---|---|
| `app/services/sector_map.py` | GICS→ETF map, symbol normalise, JSON load/save |
| `app/services/backtest_service.py` | multi-factor residual; `mom_12_1_sector_resid` in `_signal_values`; demean inject |
| `scripts/build_ticker_sector_map.py` | SP500 CSV + FMP gap fill |
| `scripts/fetch_sector_etfs_to_snapshot.py` | Alpaca → snapshot `benchmark_prices` |
| `scripts/run_sector_residual_research.py` | race guard, IC, optional A/B, reports |
| `data/research/ticker_sector_map.json` | persisted labels (research only) |

---

## Artifacts

- JSON: `reports/sector-residual-20260719-083356.json`
- MD copy: `reports/sector-residual-20260719-083356.md`