Files
signal-platform/app/services/breadth_service.py
T
dennisthiessen 824c15cf69 feat: breadth-divergence early-warning indicator + event study
Adds a leading-by-construction candidate and the harness to measure whether it
actually leads regime breaks, before any of it earns weight in the live index.

- breadth_service: % of the stored universe above its own 200-DMA + a divergence
  score (benchmark price up while breadth falls, nudged by low breadth). Genuinely
  leading because it keys on divergence, not level. Not wired into the live score.
- event_study_service: detect drawdown events on the benchmark, then measure each
  indicator's median lead time (event-centered) and precision/recall vs. the base
  rate (signal-centered). Compares breadth-divergence against the deterministic
  coincident price composite (reuses the regime price sub-scores). Price/breadth
  only — reproducible, no LLM/FRED.
- Manual "Event Study" job (Admin → Jobs), GET /regime/event-study, and an
  inline early-warning panel on the Regime tab with an honest small-sample caveat.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-26 14:08:52 +02:00

119 lines
4.5 KiB
Python

"""Market-breadth early-warning indicator (from the stored universe OHLCV).
Breadth is a genuinely *leading* construct: a few mega-caps can keep an index
rising while participation narrows underneath — the classic pre-top divergence.
We measure it from the OHLCV we already store for the whole universe, so it costs
no new data source.
Two layers:
- breadth = % of the universe trading above its own 200-DMA (0-100).
- divergence = an early-warning score (0-100, high = fragile): the benchmark
price rising *while* breadth falls, plus a nudge for already-low breadth.
This module only *computes* the indicator. It is deliberately NOT wired into the
live regime index yet — the event study measures whether it actually leads before
it earns any weight.
"""
from __future__ import annotations
import logging
from datetime import date
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from app.models.ticker import Ticker
from app.services.price_service import query_ohlcv
logger = logging.getLogger(__name__)
Series = list[tuple[date, float]]
def _breadth_from_closes(
closes_by_symbol: dict[str, Series], window: int = 200, min_tickers: int = 20
) -> dict[date, float]:
"""Pure core: % of symbols above their own rolling SMA(window), per date.
Each symbol's SMA is computed once with a sliding sum (O(bars)); dates with
fewer than ``min_tickers`` qualifying names are dropped (too thin to trust).
"""
counts: dict[date, list[int]] = {} # date -> [above, total]
for series in closes_by_symbol.values():
ordered = sorted(series, key=lambda x: x[0])
dates = [d for d, _ in ordered]
closes = [c for _, c in ordered]
if len(closes) < window:
continue
running = sum(closes[:window])
for i in range(window - 1, len(closes)):
if i >= window:
running += closes[i] - closes[i - window]
sma = running / window
entry = counts.setdefault(dates[i], [0, 0])
entry[1] += 1
if closes[i] > sma:
entry[0] += 1
return {
d: round(above / total * 100.0, 2)
for d, (above, total) in counts.items()
if total >= min_tickers
}
def compute_divergence_series(
breadth: dict[date, float], benchmark_closes: Series, lookback: int = 20
) -> dict[date, float]:
"""Early-warning score (0-100, high = fragile) per date.
Fragility rises when the benchmark price climbs over ``lookback`` days while
breadth deteriorates over the same window, and is nudged up when the absolute
breadth level is already low. It is the *divergence* (not the level) that
makes this leading.
"""
bench = {d: c for d, c in benchmark_closes}
common = sorted(d for d in bench if d in breadth)
out: dict[date, float] = {}
for i in range(lookback, len(common)):
d, d0 = common[i], common[i - lookback]
price_past = bench[d0]
if price_past <= 0:
continue
price_ret = (bench[d] / price_past - 1.0) * 100.0 # %
breadth_chg = breadth[d] - breadth[d0] # percentage points
raw = price_ret - breadth_chg # price up & breadth down -> large
score = 50.0 + raw * 2.0 + (50.0 - breadth[d]) * 0.4
out[d] = max(0.0, min(100.0, round(score, 2)))
return out
async def _load_universe_closes(db: AsyncSession) -> dict[str, Series]:
result = await db.execute(select(Ticker).order_by(Ticker.symbol))
closes_by_symbol: dict[str, Series] = {}
for ticker in result.scalars().all():
try:
records = await query_ohlcv(db, ticker.symbol)
except Exception:
logger.exception("Breadth: OHLCV load failed for %s", ticker.symbol)
continue
if records:
closes_by_symbol[ticker.symbol] = [(r.date, float(r.close)) for r in records]
return closes_by_symbol
async def compute_breadth_series(
db: AsyncSession, window: int = 200, min_tickers: int = 20
) -> dict[date, float]:
"""Historical breadth series across the stored universe (for the event study)."""
closes_by_symbol = await _load_universe_closes(db)
return _breadth_from_closes(closes_by_symbol, window, min_tickers)
async def compute_breadth_today(db: AsyncSession) -> float | None:
"""Latest breadth reading (thin wrapper, for future live use)."""
series = await compute_breadth_series(db)
if not series:
return None
return series[max(series)]