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signal-platform/tests/unit/test_signal_eval.py
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dennisthiessen 099846513b
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deepen OHLCV history + make the factor-IC pass honest about overlap/regime
Two changes so the cross-sectional signal results can actually be trusted.

(a) History depth — the binding constraint. Ingestion defaulted to 365 days, so
long-lookback factors (12-month momentum, 52-week high) were only computable on a
handful of weeks at the tail, and every IC reflected a single market regime.
- New `settings.ohlcv_history_days` (default 1825 ≈ 5y); new tickers backfill this
  far instead of 1 year.
- New manual "data_backfill" job (Admin → Jobs) re-fetches the full window for
  every ticker, ignoring incremental resume — run once to deepen existing
  1-year histories. Idempotent (upsert); resumes after rate limits.

(b) Factor-IC honesty. The IC was averaged over weekly rebalances whose 30-day
forward windows overlap, inflating the t-stat ~sqrt(6)x.
- IC now measured on NON-OVERLAPPING windows (weeks thinned to ~HORIZON apart).
- Each signal carries a `reliable` flag (>= 12 independent windows); BacktestPanel
  greys out and de-stars thin signals so a lucky 9-week IC of 0.3 can't masquerade
  as an edge.

332 backend tests pass; frontend build clean. No migration (config + job + an
added JSON field on the cached backtest report).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-23 18:20:59 +02:00

159 lines
6.5 KiB
Python

"""Tests for the cross-sectional signal-evaluation (factor IC) pass."""
from __future__ import annotations
import random
from datetime import date, timedelta
from types import SimpleNamespace
from app.services import backtest_service as bt
# ---------------------------------------------------------------------------
# Rank-correlation primitives
# ---------------------------------------------------------------------------
def test_spearman_monotonic_is_one():
xs = [1.0, 2.0, 3.0, 4.0, 5.0]
ys = [10.0, 20.0, 30.0, 40.0, 50.0]
assert bt._spearman(xs, ys) == 1.0
def test_spearman_inverse_is_minus_one():
xs = [1.0, 2.0, 3.0, 4.0, 5.0]
ys = [5.0, 4.0, 3.0, 2.0, 1.0]
assert bt._spearman(xs, ys) == -1.0
def test_spearman_handles_ties_without_crashing():
xs = [1.0, 1.0, 2.0, 2.0, 3.0]
ys = [1.0, 2.0, 2.0, 3.0, 3.0]
ic = bt._spearman(xs, ys)
assert ic is not None and 0.0 < ic <= 1.0
def test_spearman_none_when_degenerate():
# A flat array has zero variance → correlation undefined.
assert bt._spearman([1.0, 1.0, 1.0, 1.0], [1.0, 2.0, 3.0, 4.0]) is None
assert bt._spearman([1.0], [2.0]) is None
def test_quintile_spread_sign_follows_signal():
# signal == fwd return: top quintile clearly beats bottom → positive spread.
pairs = [(float(i), float(i)) for i in range(20)]
spread = bt._quintile_spread(pairs)
assert spread is not None and spread > 0
# Top quintile mean (17,18,19,16) - bottom (0,1,2,3) = 16.0
assert spread == (17 + 18 + 19 + 16) / 4 - (0 + 1 + 2 + 3) / 4
def test_quintile_spread_none_when_too_few():
assert bt._quintile_spread([(1.0, 1.0)] * 9) is None
# ---------------------------------------------------------------------------
# Signal value extraction (point-in-time, price-only)
# ---------------------------------------------------------------------------
def test_signal_values_momentum_and_trend():
# Steadily rising series so every lookback is positive and trend is above SMA.
closes = [100.0 * (1.01 ** k) for k in range(300)]
i = 299
vals = bt._signal_values(closes, closes, i)
assert vals["mom_12_1"] > 0 # up over the 12→1 month window
assert vals["trend_200"] > 0 # price above its 200-bar SMA in an uptrend
# 12-1 momentum skips the last month: close[i-21] / close[i-252] - 1
assert vals["mom_12_1"] == closes[i - 21] / closes[i - 252] - 1.0
# Strictly rising → today IS the 52-week high (highs==closes here) → ratio 1.0
assert vals["high_52w"] == 1.0
assert vals["vol_6m"] > 0 # realized vol is defined and positive
def test_signal_values_drops_signals_without_enough_history():
closes = [100.0 + k for k in range(80)] # only 80 bars
vals = bt._signal_values(closes, closes, 79)
assert "mom_3_1" in vals # needs 63 bars of lookback — present
assert "mom_6_1" not in vals # needs 126 — absent
assert "mom_12_1" not in vals # needs 252 — absent
assert "trend_200" not in vals # needs 200 — absent
assert "high_52w" not in vals # needs 252 — absent
assert "vol_6m" not in vals # needs 126 — absent
# ---------------------------------------------------------------------------
# End-to-end aggregation: a predictive signal scores, noise does not
# ---------------------------------------------------------------------------
def _records(closes: list[float]) -> list[SimpleNamespace]:
start = date(2020, 1, 1)
return [
SimpleNamespace(date=start + timedelta(days=k), close=c, high=c)
for k, c in enumerate(closes)
]
def test_signal_evaluation_separates_edge_from_noise():
rng = random.Random(42)
# 120 consecutive weeks, 40 names each. After non-overlapping thinning
# (stride = HORIZON/5 = 6) that leaves 20 independent windows — above the
# reliability bar. "edge" perfectly orders the forward return; "noise" is
# independent of it.
collected: dict = {"edge": {}, "noise": {}}
for week in range(120):
edge_recs = []
noise_recs = []
for _ in range(40):
fwd = rng.gauss(0, 0.05)
edge_recs.append((fwd, fwd)) # signal == fwd → IC = 1
noise_recs.append((rng.gauss(0, 1), fwd)) # signal ⟂ fwd → IC ≈ 0
collected["edge"][(2020, week)] = edge_recs
collected["noise"][(2020, week)] = noise_recs
rows = {r["signal"]: r for r in bt._signal_evaluation(collected)}
assert rows["edge"]["mean_ic"] == 1.0
assert rows["edge"]["weeks"] == 20 # 120 weeks thinned to non-overlapping
assert rows["edge"]["reliable"] is True
assert rows["edge"]["ic_positive_pct"] == 100.0
assert rows["edge"]["mean_quintile_spread"] > 0
assert abs(rows["noise"]["mean_ic"]) < 0.15 # indistinguishable from zero
# Rows are sorted by mean_ic descending: the real signal ranks first.
assert bt._signal_evaluation(collected)[0]["signal"] == "edge"
def test_signal_evaluation_flags_too_few_windows_unreliable():
# 5 adjacent weeks collapse to a single non-overlapping window → unreliable.
collected: dict = {
"edge": {(2020, w): [(float(i), float(i)) for i in range(40)] for w in range(5)}
}
row = bt._signal_evaluation(collected)[0]
assert row["weeks"] == 1
assert row["reliable"] is False
def test_nonoverlapping_weeks_thins_by_stride():
weeks = [(2020, w) for w in range(1, 13)] # 12 consecutive ISO weeks
kept = bt._nonoverlapping_weeks(weeks, stride=6)
assert kept == [(2020, 1), (2020, 7)] # 6 apart, no overlap
# Stride 1 keeps everything; ordering is chronological.
assert bt._nonoverlapping_weeks(list(reversed(weeks)), stride=1) == weeks
def test_signal_evaluation_skips_thin_weeks():
# A week with fewer than MIN_CROSS_SECTION names is ignored entirely.
collected: dict = {"edge": {(2020, 1): [(1.0, 1.0)] * (bt.MIN_CROSS_SECTION - 1)}}
assert bt._signal_evaluation(collected) == []
def test_accumulate_signal_series_emits_weekly_pairs():
closes = [100.0 * (1.005 ** k) for k in range(400)]
collected: dict = {}
from collections import defaultdict
collected = defaultdict(lambda: defaultdict(list))
bt._accumulate_signal_series(_records(closes), collected)
# The long, rising series should yield momentum + trend observations...
assert "mom_12_1" in collected and len(collected["mom_12_1"]) > 0
# ...one per ISO week, with a forward return attached to each pair.
sample = next(iter(collected["mom_12_1"].values()))
assert all(len(pair) == 2 for pair in sample)