Derived by the Research Lead from Zhang & Urquhart, 'Pairs trading across Mainland China and Hong Kong stockmarkets' (International Journal of Finance and Economics, 2018), as summarised on BigQuant (https://bigquant.com/wiki/doc/zNkp9XcBmh). The full paper PDF could not be read (HTTP 404), so only the abstract's findings were available. The page's only image is the BigQuant site favicon (a blue logo icon), not a chart, so it adds no evidence. Findings from the source: pairs trading inside either market alone earns no significant abnormal return; pairs trading ACROSS the mainland and Hong Kong markets earned about 9% a year in abnormal returns after risk and costs from 1996 to 2017; profitability varies over time and fell after 2012; and the strategy does best in long range-bound markets. The source attributes the edge to irrational demand combined with limits to arbitrage between the segmented markets. The rules below are the Research Lead's operationalization, not the authors' strategy. I use the cleanest cross-market pair available: the A-share and H-share of the SAME company, which are claims on identical cash flows kept apart by capital controls and Stock Connect quotas. Constraint: CNEQ and HKEQ are both CASH accounts, so the rich twin cannot be shorted and a true two-leg spread cannot be expressed. Prior art: run 17503f75 held only the cheap twin with no hedge. Its analyst ruled that this unhedged form cannot measure A/H convergence, because the long leg carries full China beta, and asked for a hedged version. This hypothesis is that hedged version. A short in FXI.USEQ (the iShares China Large-Cap ETF, whose top holdings are H-shares of the same banks, insurers and oil majors) is sized against the long book, so the remaining P&L is the cheap twin's catch-up plus single-name noise, not China market direction. Universe: 11 verified A/H twins with 1-DAY bars on both venues from 2018-01-02: ICBC 1398.HKEQ/601398.CNEQ, CCB 0939/601939, Bank of China 3988/601988, Agricultural Bank 1288/601288, Bank of Communications 3328/601328, China Merchants Bank 3968/600036, Ping An 2318/601318, China Life 2628/601628, PetroChina 0857/601857, Sinopec 0386/600028, BYD 1211/002594. The universe is fixed. These are long-standing large-cap dual listings, all listed on both exchanges before 2018, so there is no survivorship selection within the test window. Execution: decisions are made at the close of the primary 2318.HKEQ daily bar (HK close 08:00 UTC); the A-share close (07:00 UTC) of the same date is already known by then. Every order fills at its own leg's next session open (next_open_fill, supported): HK legs at the next HK open, A-share legs at the next mainland open, and the FXI hedge at the next US open (13:30 UTC the same calendar day). The hedge is therefore placed about 12 hours before the HK/CN entry fills. That is a known timing mismatch and stays in the test. Each leg is held for many sessions (expected median ~15-25), so CNEQ T+1 is never binding. Costs: HKEQ about 0.22% statutory round trip (stamp duty on both sides) plus about 0.08% spread; CNEQ about 0.10% plus 0.04% spread; FXI about 0.03% spread plus modeled borrow. Precondition: the previous A/H run showed total_commission 0.0 on HKEQ/CNEQ. The backtest must show non-zero commissions on both venues before its economics are read. Risk route (b): signal exits and capped sizing. Each long twin is 8% of reference equity (max 8 concurrent, so 64% gross long), and the FXI short is at most 64% of reference equity. Unlevered per leg; the only margin used is Reg-T on the USEQ hedge.