AVAX USD-M Path-Efficiency-Gated Time-Series Momentum, Long-Short (AVAXUSDT.BINANCE 4H — take the trend ONLY when the Kaufman Efficiency Ratio says the path is directional enough for the move to clear fees; stand flat in chop, chandelier trailing exit, 3-parameter, pure OHLCV)

A LONG-SHORT, single-instrument, pure-OHLCV directional trend follower on AVAXUSDT.BINANCE (USD-M perpetual), 4H bars, ~6 years of history (2020-09-23 -> today, ~13,000 bars). It stays inside the ONE mechanism family that has actually survived in this factory (directional Binance USD-M time-series momentum on liquid majors with a single orthogonal confirmation gate, long-short, ATR trailing exit) but replaces the confirmation gate with one that has never been tried here and that attacks the exact failure mode that kills these strategies. Every dead sibling in the failure store (XRP OI-expansion momentum avg_trade 0.051%, SOL OI-confirmed Donchian 0.177% with PF 0.96, LINK/DOGE variants) died the same way: the gate (open interest, liquidations, funding) filtered on a DERIVATIVES-positioning variable that is only loosely related to whether the subsequent PRICE PATH is tradeable. The strategy kept entering during choppy, high-noise advances where the net displacement per unit of price travel is small, so the average trade return landed at or below the 0.10% round-trip fee. Trend-following PnL is not proportional to the size of the move, it is proportional to NET DISPLACEMENT MINUS PATH TRAVEL (you pay for every whipsaw through the stop and every re-entry). The Kaufman Efficiency Ratio, ER(n) = |C_t - C_{t-n}| / sum_{i=t-n+1..t} |C_i - C_{i-1}|, measures exactly that ratio directly from the bars: ER near 1 = a clean one-way move, ER near 0 = a random walk that happens to have drifted. Gating entries on ER is a direct, mechanical filter on expected per-trade capture, i.e. on avg_trade_return_pct itself — the metric that has killed 490 hypotheses as fee_edge. Symbol choice is deliberate: AVAXUSDT, a liquid Binance USD-M major listed 2020-09-23 that has ZERO prior experiments in the corpus, while BTC (44% of all corpus experiments) and the already-promoted ETH/ADA/BNB names are avoided. The venue stays BINANCE USD-M despite its 70% corpus share because lessons L94 and L100 state explicitly that this mechanism family is Binance-USD-M-specific and that Bybit / Hyperliquid / COIN-M reroutes are themselves the reason the clones die; moving venue to satisfy a quota would be knowingly proposing a death. Direction is LONG-SHORT (14.8% of corpus vs 85.2% long-only), which is the most under-represented dimension I can fill without breaking the mechanism. FEE ARITHMETIC (mandatory). AVAX 4H ATR(14) runs ~1.4-1.8% of price. The ER gate at er_min ~0.35 fires on roughly the top quintile of 5-day windows by path efficiency; in those windows the 30-bar (5-day) net displacement averages ~8-11% of price with the trailing exit typically extending the hold to 6-12 days. A 3xATR chandelier gives back ~4.5% at the exit, so winners realise ~4-6% and stopped trades lose ~4.5%, at a trend-follower hit rate of ~35-40%. Conservatively the honest expectation is ~0.40-0.50% of notional per trade versus a 0.10% USD-M round-trip = 4-5x the fee floor. Cadence is ~35-55 entries/year (the ER gate is off roughly 80% of the time), i.e. ~1 trade per week, ~250 trades over the 6-year history — far from the >5 trades/day fee-drag zone, and enough sample for walk-forward and a holdout to be powered. Three parameters only (lookback n, er_min, atr_mult); ER and ATR are both O(1) rolling updates so there is no per-bar rescan of history (the sandbox_timeout failure mode does not apply — no supplementary series are read at all).