longbridge-pairs-trading Statistical-arbitrage strategy for a pair of correlated securities. Tests for cointegration, estimates hedge ratio, computes spread Z-score, and outputs actionable long/short signals with half-life and position sizing guidance. Response language : match the user's input language — Simplified Chinese / Traditional Chinese / English. When to use - User provides two ticker symbols and asks for pairs trading analysis, spread mean-reversion, cointegration test, or statistical arbitrage. - Triggers: "MSFT 和 GOOGL 配对交易", "HSBC vs StanChart 协整", "pairs trade AAPL MSFT", "价差均值…