A cross-venue, long/short, multi-asset daily strategy. Signals come from Binance USD-M perp and Binance spot daily bars. They are used only as signals and never traded. Execution is on OKX USDT perpetual swaps, a venue the corpus barely uses (2.5% of experiments). Universe: LINK, ADA, AVAX, DOT, ATOM, UNI. The rule picks pre-2021 large caps that have continuous 1-DAY bars on all three venues from 2020 (OKX history verified back to 2020-03..09). Signal per coin per daily close: perp_share = perp_base_volume / (perp_base_volume + spot_base_volume), both from Binance, same coin, base units. psz is the z-score of perp_share over the trailing `share_lookback` days. ret7 is the 7-day return of the OKX swap close. Thesis: an advance carried by spot buying is financed with cash. It has no liquidation overhang, so it tends to continue. This is the mechanism behind the promoted long-only spot volume-share strategy. An advance carried disproportionately by perps is financed with leverage. Crowded longs, rising funding and liquidation fuel make it fragile, so it tends to unwind. The hypothesis tests BOTH sides of that mechanism as a long/short book on a different venue. It does not re-run the long-only spot version. Execution substitution: decisions are made on the daily close and filled by a market order at that close. On a 24/7 venue that price is the next bar's open (the registry's use_equivalent for next_bar_open_fill). Protective stops are intrabar reduce-only stop-market orders matched by the platform (supported). There is no exchange-resting requirement. Sizing: each position's notional = equity * risk_per_trade / (atr_stop_mult * ATR14%), capped at 15% of equity per coin, with at most 6 concurrent positions (one net position per coin) and leverage 1.5. Gross exposure is at most ~90% of equity times 1.5. Platform defaults apply where unstated. Funding on the OKX swaps is charged through the funding ledger: longs in rallies typically pay it and shorts receive it.