描述
Financial regulatory knowledge base — A-shares (10% / 5% ST price limits, T+1 settlement, short-selling rules, new delisting rules), HK (T+0 short-selling, no price limits, odd-lot / grey market, profit test, insider dealing ordinance), US (PDT rule $25k threshold, Reg T margin, circuit breakers, SEC rules), crypto regulation, cross-border tax basics. Triggers: "监管规则", "涨跌停", "T+1", "融券", "退市", "做空规则", "PDT规则", "熔断", "保证金", "印花税", "監管規則", "漲跌停", "融券", "退市", "做空規則", "PDT規則", "熔斷", "保證金", "印花稅", "regulatory rules", "circuit breaker", "short selling rules", "PDT rule", "margin requirements", "stamp duty", "delisting rules", "trading rules", "settlement rules".