A long-only, MULTI-INSTRUMENT (signal from BTC, trade on ADA), single-timeframe strategy on ADAUSDT.BINANCE 4H bars using BTCUSDT.BINANCE 4H as the LEADING signal. Implements the analyst's EXPLICIT prescriptive recommendation from the ADAMultiBarDownStreakReversal abandon: 'Next attempts should explore: (d) cross-instrument signals (BTC-leads-ADA or BTC-ETH-correlation breakdown). These are mechanism classes NOT yet tried this session.' The mechanism: when BTC makes a 20-bar Donchian-high breakout AND ADA has NOT YET made a corresponding breakout, enter long on ADA expecting it to follow within 1-3 bars. Documented in Liu-Tsyvinski 2018 'Risks and Returns of Cryptocurrency' which showed BTC leads major alts by 1-3 bars at the 4H timeframe. CROSS-INSTRUMENT structural signal — not in the failed families: (a) NOT breakout on ADA itself (which decayed in 2025+); (b) NOT mean-reversion-within-trend on ADA (which is empirically dead); (c) NOT statistical/momentum/range on ADA (all arbitraged out); (d) IS a structural lead-lag relationship between two correlated instruments. The mechanism exploits the documented sequencing: institutional flow hits BTC first (highest liquidity), then propagates to alts within hours. Capturing the propagation lag generates alpha that single-instrument ADA strategies cannot access.