A LONG-SHORT, SINGLE-INSTRUMENT, 1-HOUR mean-reversion strategy on ETHUSD.HYPERLIQUID that fades stretched dislocations on both sides (buy stretched-below-mean, short stretched-above-mean) and exits on reversion toward an intraday mean (rolling VWAP / EMA). It is deliberately the ONE non-redundant slot left in the clean-evaluable corner: three HL cadence probes are already pending (BTC 1H momentum-LS, BTC 4H momentum-LS, ETH daily high-turnover reversal), so another momentum/breakout probe would duplicate them. This is the MECHANISM-MATCHED ETH complement at the highest-holdout-density non-sub-hourly cadence. Rationale chain from the fully-mapped constraints: only HL BTC/ETH size cleanly (BINANCE USD-M/COIN-M over-exposure-broken, spot-CASH MTM broken, multi/options broken, census data-walled, HL SOL data-poisoned); HL daily is deep but the 15-day holdout is too sparse (~15 bars); HL 15-min is data-walled (~2mo, banned, 5x). The remaining hope is a deep intraday cadence; 1H is the BEST holdout-density candidate (~24 bars/day -> ~360 holdout bars vs ~90 at 4H, ~15 daily) and is explicitly NOT sub-hourly. ASSET-SELECTIVITY: ETH lacked momentum/breakout edge (it CHOPS), so the ETH-appropriate mechanism is reversion (the pending BTC-1H book correctly uses momentum on the trending asset; this uses reversion on the choppy one). CRITICAL DESIGN FIX: every prior VWAP-reversion run failed on INVERTED payoff geometry (avg_win < avg_loss: ETH long/flat 567<678, ETH LS 467<664, SOL fade) because the mean-touch target was smaller than the ATR stop. This is fixed with an EXPLICIT GEOMETRY GATE: only enter when the distance from price to the reversion target (the mean) is >= geom_mult x the stop distance (geom_mult > 1), net of the ~0.09% HL round-trip, so avg_win > avg_loss BY CONSTRUCTION; entries failing the gate are skipped. Bug-avoiding: pure OHLCV, ONE fixed-fractional size per entry, NO dynamic resizing, leverage 1.0, dual flat guard, flip-via-flat. REGIME GATE prevents fading genuine trends (no dip-buy in strong downtrend, no rip-fade in strong uptrend). Fills the dominant direction gap (long_only 85.9% vs <=55%) and under-weight HL venue (7.2% vs >=20%). PRE-REGISTERED ACCEPTANCE (hard kill-switches, evaluated FIRST, shared with the BTC-1H probe to avoid thrash): (1) DATA-DEPTH — 1H HL ETH data must span >= ~2 years AND the 15-day holdout contain >= ~10 trades; else the sub-daily HL data wall extends to 1H -> ABANDON & ESCALATE (NOT iterate, NOT optimize). (2) GEOMETRY — realized avg_win > avg_loss must hold; if not, the geometry gate failed -> abandon. (3) SIZING — avg_position_pct ~<=100%, no impossible intraday equity jump; else abandon & escalate as reproducer. Low parameter count (mean lookback, stretch threshold, geom_mult, regime EMA, ATR stop, time stop).