COIN-M Open-Interest Deleveraging-Flush Reversal, Long-Short (Single-Instrument ETHUSD_PERP.BINANCE_CM — Fade Price Moves Driven by a Sharp CONTRACTION in Open Interest, i.e. Positions Closing Rather Than New Conviction Entering; OI-Rate-of-Change Gated, 2-Parameter)

A LONG-SHORT, SINGLE-INSTRUMENT, SINGLE-VENUE mean-reversion strategy on the ETHUSD_PERP.BINANCE_CM inverse perpetual. The signal is ORTHOGONAL to price: the rate-of-change of OPEN INTEREST (a position-count feed already in the catalog), not any indicator computed on the price series. Core insight — the information content of a price move depends on whether OPEN INTEREST is EXPANDING or CONTRACTING. When price moves sharply WHILE open interest is sharply CONTRACTING, the move is being driven by existing positions being CLOSED (deleveraging / stop-runs / margin reduction), not by new informed capital taking a side. Flow that must exit for balance-sheet reasons is price-insensitive and over-extends, then reverts once the deleveraging clears. So: OI-contraction + sharp price DOWN = longs flushing out → fade LONG; OI-contraction + sharp price UP = shorts covering → fade SHORT. This is mechanistically DISTINCT from a liquidation-cascade fade (which keys off the discrete liquidation print at the violent instant): here the trigger is the slower, hours-scale drop in the position count itself, catching deleveraging flushes that never register as a single large liquidation. Single venue + single instrument → both the 1h bars and the OI feed are jointly available in the Layer-3 sandbox (no cross-venue/multi-leg verification_loop risk). Deliberately 2-parameter to resist the overfit deaths that dominate the failure log.