Binance-vs-OKX Same-Coin Funding-Differential Carry: Dollar-Neutral Long Cheap-Funding Perp / Short Rich-Funding Perp When the Trailing 3-Day Venue Funding Gap Exceeds 0.35% (5 mid-cap alts: TRB, AXS, ZIL, API3, ETC; 1H decision bars; flat most of the time)

A cross-venue, market-neutral carry trade on one coin at a time. Each coin is held on two venues at once: the Binance USD-M perpetual (<COIN>USDT.BINANCE) and the OKX USDT swap (<COIN>USDT.OKX). Both settle funding every 8h, but their crowds are different, so their funding rates diverge. On mid-cap alts the divergence is large and persistent. When the trailing 3-day sum of (OKX funding - Binance funding) is beyond the threshold, short the perp on the venue paying the higher funding and long the other venue's perp in equal notional. Price exposure cancels, because both legs are the same coin. What is collected is the funding differential, plus any convergence of the cross-venue price premium, which usually points the same way as the rich-funding venue. This is NOT a directional perp trade gated on funding (lesson L111). There is no price bet at all: the P&L source is the cash flow itself. It is also not the dead 12-name same-venue funding-carry basket, which earned the funding LEVEL on one venue. This trade earns the cross-venue funding SPREAD with both legs on the same coin. Point-in-time pre-study (funding_rates table, rows de-duplicated per (symbol, exchange, timestamp) because Binance rows are stored up to 5x; daily sums; 2022-02 to 2026-09). Across ~160 common USDT symbols, sign(trailing-3d gap) x next-10d gap rises monotonically with the size of the gap: 0.06% for |gap| < 0.1%, 0.19% for 0.1-0.2%, 0.29% for 0.2-0.3%, 0.43% for 0.3-0.4%, 0.49-0.61% above that. The gap therefore persists rather than mean-reverting immediately. Majors (BTC, ETH, SOL, XRP, DOGE) almost never reach a 0.25% 3-day gap, so the edge lives in mid-caps. Universe capped at 5 coins / 10 instruments (lesson L173). The 5 were chosen from coins that (a) fire most often and (b) have OKX 1H bars in the catalog from 2022 or earlier (ENJ/ONT/FIL OKX bars start 2024-2026, so they were excluded). This selection is in-sample, and the analyst should know that. Episode study on these 5 (first day |3d gap| crosses 0.35%): 84 episodes. Mean next-7-day captured differential 0.674%, median 0.234%, 52% of episodes capture more than 0.2%. By year: 2022 0.66% (n=28), 2023 0.43% (26), 2024 -0.36% (6), 2025 0.61% (8), 2026 1.52% (16). The distribution is right-skewed and 2024 was a bad year. Expect a modest Sharpe, not a spectacular one. Data: bars from the ParquetDataCatalog for the 10 instruments at 1-HOUR. Binance funding comes from BinanceFuturesDataCollector/FundingCollector, OKX funding from OkxCollector (API + daily CDN from 2022-01-17). Both are in PG funding_rates under exchange binance/okx. The strategy MUST read each leg's own series via the per-leg supp `funding_rates_by_instrument` (supp_collector loads it for every linear-perp leg), accessed point-in-time (supp_as_of / supp_window semantics: observations at or before the current bar only). Funding accrual on held positions is applied by funding_accrual for both BINANCE and OKX, so the backtest P&L includes the carry itself.