Δopen = 100 × (C(t) / R_XYZ(session open) − 1)UTC composite reference combines the midpoints of valid Binance and Hyperliquid trade[XYZ] best bids and offers. Binance USDT quotes are converted with the observed Chainlink USDT/USD feed; XYZ quotes are in USD. Both inputs are required. A lone oracle or quote is never substituted for a composite.
The two USD midquotes are combined geometrically: C = exp(wB × ln(B_USD) + wX × ln(X_USD)). The rolling VECM estimates the shared price component and the weights sum to one. Before a valid fit, available liquidity weights are identified as a prior. If a new fit is not valid, previous learned weights may be retained. Retaining weights is different from retaining an old price.
The primary comparison uses the first valid XYZ oracle observation within two minutes after the latest scheduled regular-session opening. It is not the exchange’s official opening price or a return between two composite prices. Before the next opening, on weekends and on holidays, the latest trading session’s baseline is retained. Accepted on-chain XYZ oracle updates can restore a baseline from before local collection started. An unavailable baseline remains unavailable. The 24-hour XYZ oracle comparison is a separate secondary measure.
Session comparisons use published 2026 schedules: 09:30 New York, 09:30 Hong Kong and 09:00 Tokyo. EWJ is a Japan equity ETF listed on NYSE Arca and uses the U.S. opening schedule. Holidays and pre-open periods retain the latest session baseline. Unsupported years and missing baselines remain unavailable. The schedule does not detect individual trading halts.
USD is the common reference unit. Binance uses USDT and XYZ uses USDC collateral; neither stablecoin is labelled as USD cash. Missing, stale or invalid quotes, excessive source divergence or invalid FX suspend new calculations. A last valid value retains its original calculation time and inputs.
The chart spans 36 hours in 72 30-minute bars. Actual stored reference OHLC takes priority. Unobserved past buckets are initially filled from Binance mark and XYZ trade OHLC using the weights and Chainlink FX observed at bootstrap; these bars are not a reconstruction of historical one-second VECM estimates and are not repeatedly reweighted. Live accepted observations update the current candle. Instruments registered for a single XYZ source use XYZ OHLC.
Calculation time, source publication time and receipt time are distinct. An absent source timestamp stays unknown. XYZ oracle and Robinhood Chain oracle values are shown separately as comparison or reference information; Robinhood is not a weighted input to this composite.