Event-driven, dollar-neutral, cross-sectional long/short on 13 Hyperliquid perpetuals using 1-DAY bars. BTCUSD.HYPERLIQUID is used only as the signal (it is never traded). The trigger is a large 3-day BTC move. At that point each alt's 3-day log return is split into an expected part (rolling 90-day beta to BTC x BTC's 3-day return) and a residual. The residual is signed by BTC's direction. A positive signed residual means the alt over-responded in BTC's direction: it rose more than its beta implies in a BTC rally, or fell less in a BTC selloff. The hypothesis is that these residuals persist rather than mean-revert. Alts that diverge from their beta in a market-wide shock are showing real information: who is being bought as the rotation target, and who is being dumped as the funding source. That information diffuses slowly over the next week or two. This is the opposite of the 'laggards catch up' intuition, and my pre-study rejected catch-up outright (see expected_edge). It is not a plain momentum rotation: there is no position unless BTC has shocked, ranking uses the beta-residual rather than raw return, and it is flat roughly 50% of the time. Venue rationale: HYPERLIQUID holds 9.1% of the corpus against a >=20% target, and long_short holds 18% against a long-only share of 82%. The design is pure OHLCV (L189) with no extra feed. Universe, chosen for multi-year HL daily history and to avoid the names in recent HL failures (SUI/INJ/SEI/TIA, AVAX/NEAR/DOT-ATOM, LINK): AAVE, BCH, LTC, UNI, CRV, FIL, ETC, XRP, ADA, BNB, DOGE, DOT, ETH. Risk: each leg is 1/6 of 75% gross, so 12.5% of equity per leg; no leverage is needed, and gross stays <=0.75x. Stop: there is no per-leg price stop, because pair P&L is what matters. A basket-level stop closes all six legs if the combined open P&L falls to -6% of equity-at-entry x gross. Max exposure is 12.5% per leg and 75% gross.