Hurst Exponent & Market Regime API
Tells you whether each market is trending, behaving like a random walk, or mean-reverting — the single most important thing to know before choosing a strategy — computed live from Yahoo Finance daily closes, no key, nothing stored. A trend-following system bleeds money in a mean-reverting market, and a fade-the-move system gets run over in a trending one; the Hurst exponent (via rescaled-range R/S analysis) measures which world you are in. A Hurst above ~0.55 means the series is persistent — moves tend to continue, so it trends and trend-following fits; near 0.5 it is a random walk with no edge either way; below ~0.45 it is anti-persistent — moves tend to reverse, so it mean-reverts and fading extremes fits. Alongside it the API returns the Kaufman Efficiency Ratio (net move divided by the total path travelled, 0 = pure noise, 1 = a perfectly straight trend), a second intuitive read on how cleanly a market is trending. The asset endpoint returns one instrument's Hurst, efficiency ratio and a regime label; the screener endpoint ranks the cross-asset universe (equities, sectors, commodities, bonds, FX and crypto; filterable by class) from most trending to most mean-reverting. This is the persistence / trend-versus-mean-reversion regime cut — distinct from the z-score stretch gauges (how far a price is from its average right now, not the structure of its moves), the multi-timeframe momentum-alignment API and the price APIs. It tells you which kind of strategy the market is paying for.
api.oanor.com/hurst-api
