ADA 4H Downside-Momentum Short-Only with Daily Bearish-Trend Confirmation on ADAUSDT.BINANCE

A SHORT-ONLY, single-instrument, multi-timeframe defensive crash-protection strategy on ADAUSDT.BINANCE — confirmed testable per the recent successful ADA-based pipeline additions (ADAKeltnerRangeTradingLongShort, ADAVolContractionSqueezeLong, ADALINKCointegrationPairsReversion60Day4H). Structurally distinct from EVERY current portfolio strategy: the promoted ETH+SOL multi-timeframe breakout is long-only; my DOGEMultiTimeframeDonchianBreakoutLong is long-only; all current pairs/cointegration strategies are dollar-neutral; the Keltner range strategy is symmetric. The portfolio has ZERO dedicated SHORT-ONLY DEFENSIVE strategies. This fills a critical role: drawdown protection during regime breaks. The mechanism: when the DAILY trend on ADA is confirmed bearish (close < 50-day SMA AND SMA slope NEGATIVE), 4H breakdowns below the 20-bar Donchian low represent confirmed continuation entries SHORT. The DAILY bearish-trend filter prevents the strategy from fading countertrend bounces during bull markets (where pure short-only is structurally money-losing in trending crypto). DOWNSIDE momentum in crypto is documented to be FASTER than upside momentum (the 'crashes are faster than rallies' asymmetry — Liu-Tsyvinski-Wu 2022): when sentiment breaks, retail panic-selling cascades through alts more aggressively than bull-cycle momentum. ADA specifically has higher retail-flow concentration than majors, making crash regimes more pronounced. The strategy activates ONLY during ~10-20% of the time when the daily trend is genuinely down — providing rare but high-conviction short exposure that diversifies the portfolio's structural long bias. Uses ONLY ADAUSDT.BINANCE 4H + Daily bars — confirmed testable, no cross-asset auto-collection issues. Fills critical gaps: (1) FIRST SHORT-ONLY DEFENSIVE strategy in portfolio (84.8% long_only → reduces toward 55% target by adding short exposure), (2) CRASH-PROTECTION mechanism class (entirely absent from current portfolio), (3) SINGLE-INSTRUMENT scope (avoids multi-instrument audit_stale traps), (4) confirmed-testable instrument. Position sizing: 18% per trade. Risk per trade: 1.5% capped by ATR stop.