Cross-Venue Cash-and-Carry Funding Harvest — Delta-Neutral LONG Binance SPOT ETH / SHORT Hyperliquid ETH Perp, Entered ONLY While HL Funding Pays Shorts, Unwound When Funding Decays (Single-Asset, 2-Leg, Market-Neutral, O(1) Implementation)

A MARKET-NEUTRAL, cross-venue funding-carry strategy that collects Hyperliquid perpetual funding on a single major (ETH) while holding zero net price exposure: LONG spot ETH on Binance + SHORT the ETH perp on Hyperliquid in equal notional. The P&L is the mechanical funding cash flow the perp short RECEIVES while the market is in contango, NOT any price bet. This deliberately fills FOUR of the most under-represented portfolio buckets at once — HYPERLIQUID venue (6.9% vs ≥20% target, the single largest gap), cross_venue (7.2% vs ≥15%), BINANCE_SPOT (11.1% vs ≥15%), and market-neutral long_short (portfolio is 85.8% long-only) — with a structural edge rather than a fragile statistical pattern. It is a DIFFERENT family from everything in the graveyard: NOT a directional trend/momentum-confluence clone (L62), NOT a fade/mean-reversion (the falsified fade families), NOT options (L64), NOT COIN-M (L65), NOT OI-breakout, and NOT a funding-EXTREME CONTRARIAN fade (that bet on price reverting and had negative edge; this makes NO price bet — it is delta-neutral and simply banks funding). It also differs from the prior abandoned Binance-only cash-and-carry BASKET in three concrete ways that address why that one died (verification_loop / 300s timeout): (1) SINGLE asset, two legs — no multi-name plumbing; (2) the funding series is loaded ONCE into a timestamp-keyed dict in __init__ and read by O(1) key lookup on each bar — there is NO per-bar rescan / min() / sorted() over history, the exact pattern that timed out the prior funding and Deribit strategies; (3) rebalancing is THRESHOLD-GATED (enter/exit only on funding crossings, a few times per month), not per-bar. Hyperliquid funding is settled HOURLY and is frequently RICHER than Binance's, so ETH in contango can pay the perp short on the order of ~0.01%/hr ≈ 0.24%/day. Both legs have ample history for validation: Binance spot ETHUSDT is multi-year, and HL ETH perp at 1d spans the full HL history (well clear of HL's sub-hourly ~5000-candle wall since decisions are made on daily/funding cadence). FEE ARITHMETIC (the load-bearing check): a full paired cycle = open 2 legs + close 2 legs. Binance SPOT round-trip ≈0.20% + Hyperliquid round-trip ≈0.09% ⇒ ≈0.29% total on the paired notional. Entry requires HL funding ≥ ~0.02%/8h-equiv (i.e., contango genuinely paying shorts); at ~0.24%/day of funding the ≈0.29% cycle cost is recovered in ≈1.3 days, and the average hold spans a multi-day-to-multi-week contango window, so a ~10-day hold banks ≈2.4% of notional in funding vs ≈0.29% fees ⇒ net ≈+2%/trade — far above the low-fee floor, and the return is a real cash flow, not a price forecast. Because the book is delta-neutral, market-wide crashes/rallies do not drive P&L; the only residual risk is the spot-vs-perp price BASIS, which is small and itself mean-reverting.