Spot Gold Off-Calendar Liquidity-Shock Absorption: Buy a >=k-Sigma 1H Down-Bar in XAUUSD.SPOTMETAL That Occurs OUTSIDE the US Macro-Release Window, Fixed 18-Hour Clock Exit, Intrabar ATR Stop (1-HOUR, long-only event trade, flat ~90% of the time, pure OHLCV)

Original Research Lead hypothesis. It moves the factory's best-surviving event shape (lesson L224/L230: buy a volatility-defined DOWN-shock, flat most of the time, exit on a fixed clock) off crypto onto spot gold, where it has never been tested. It adds one gold-specific filter that separates liquidity shocks from information shocks. On XAUUSD.SPOTMETAL 1-HOUR bars (Dukascopy mid, history from 2003), a shock bar is a bar whose close-to-close log return is <= -k x sigma, where sigma is the standard deviation of the trailing N 1H returns (session bars only; the 17:00-18:00 NY break and weekends are closed market, not bars). The shock must ALSO fall OUTSIDE the scheduled US macro-release window: it must not close between 08:00 and 11:00 America/New_York on a weekday, or between 14:00 and 15:00 NY on any day, which covers 08:30 data, 10:00 data and 14:00 FOMC statements. Those slots carry real information, and the factory already tests continuation there (the Spot Gold US 08:30 ET Data-Slot Shock Continuation run). It must also not close in the first bar after the Sunday 18:00 reopen, because a weekend gap is a different mechanism. The remaining shocks hit in the thin Asian hours, at the London open or late in the US afternoon. Gold has no circuit breakers and large stop clusters below round numbers, so these drops are mostly forced liquidations and stop runs through thin books (e.g. the Aug 2021 Asian flash crash, Apr 2013 is the counter-example) that institutional buyers absorb within hours to a day. Entry is a market order decided at the shock bar's close. SPOTMETAL is a session venue, so the platform fills it at the NEXT 1H bar's open (next_open_fill, supported). Exit is on a fixed clock 18 session bars after entry, with an intrabar protective stop (stop_market, reduce-only, supported on session venues): a session that opens through the stop fills at that open. Cost arithmetic: the median 1H gold return std is about 0.18%, so a k=3 shock is a drop of about 0.55% or more, and half of the 1H ATR is about 0.1%. Capturing a third of the shock as retracement gives about 0.18% gross. Costs are a spread of about 0.015% round trip plus long overnight financing of about (fed funds + 2.5%)/365, roughly 0.012-0.02% for one 17:00 crossing (x3 on Wednesday). The net is about 0.15% per trade, roughly 5x the cost. Firing rate: gold 1H returns are fat-tailed, so 3-sigma down-bars outside the release window should occur about 25-50 times a year, roughly 500-1,000 events over 2003-2026, comfortably above the ~10/yr verification floor. Pre-registered benchmark (L170/L224): the analyst should compare the mean 18-bar forward return after a qualifying shock with the unconditional mean 18-bar long return on gold over the same span (gold's secular drift is about +0.03%/day). The claimed edge is the INCREMENT over that drift, and the in-window shocks (the ones excluded) serve as a placebo that should show no reversal or show continuation. Risk route (a): the stop sits stop_atr_mult x ATR(14, 1H) below the fill, and notional is sized so the stop loses risk_pct = 1% of equity. Typically that means a 0.6% stop distance and about 1.7x notional, capped at 3x equity. Gold's daily std is about 1.0%, so 3x is about 57% annualized position volatility, inside the 120% cap and the 5x leverage cap. The liquidation buffer at the 20x venue margin is far more than 8 daily moves. Only one position is open at a time, and a new shock during a live trade is ignored.

This implements the hypothesis as written, using only OHLCV. sigma is the sample std of the trailing N 1H log returns and excludes the shock bar itself; the signal is that z-score, a continuous value every bar. Macro windows are tested on the bar's close timestamp in New York time with both ends inclusive, so bars closing 08:00-11:00 (weekday) or 14:00-15:00 are excluded; this covers the 08:30, 10:00 and 14:00 releases. The Sunday-reopen bar is identified as a Sunday NY bar more than 6h after the previous bar (reopen_gap_hours, a detection constant, not tuned). The hold counter counts session bars from the bar the fill occurred on, and all trade state is scalar attributes. leverage=5.0 matches the risk profile's max_leverage and leaves margin headroom; size is capped at 3x equity (max_notional_x, fixed). At a typical 0.6% stop the notional is about 1.7x. The capabilities used are next_open_fill and stop_order_session_venue (submit_stop_order, reduce_only, crossed_policy=market so a gap through the stop exits at the next open); both are listed as supported. Tunables follow the optimization plan exactly: shock_k, hold_bars, stop_atr_mult and sigma_lookback. The code does not clamp any parameter, so no _param_bounds are declared.