[20050606]RS21871_通过交易规则.pdf

Congressional Research Service The Library of CongressCRS Report for CongressReceived through the CRS WebOrder Code RS21871Updated June 6, 2005The Trade-Through Rulename redactedSpecialist in Public FinanceGovernment and Finance DivisionSummaryThe trade-through rule mandates that when a stock is traded in more than onemarket, transactions may not occur in one market if a better price is offered on anothermarket. Defenders of the rule portray it as an essential protection for investors,particularly small investors who find it difficult to monitor their brokers performance.Opponents argue that its principal effect is anti-competitive; that it protects traditionalexchanges where brokers and dealers meet face to face on trading floors fromnewer forms of trading based on automatic matching of buy and sell orders. In April2005, the Securities and Exchange Commission (SEC) adopted new regulationsmodifying the trade-through rule, which it described as antiquated. The new RegulationNMS requires that investors receive the best price available among price quotations thatare displayed electronically and immediately available for execution. The new rules alsomandate improved market access, to a