其它单纯的 discount brokers 最多就是把你下的单子卖给别的交易所去成交， IB 本身即是券商，也是自己参与交易的庄家之一，尤其是股票期权上的大庄家。IB 老板是做软件出身的，是推动市场向电子交易的先驱之一。我猜在IB下的单子很大比例都是内部被IB本身的交易软件给 match 了，至于是不是最好价钱，说不清
Thomas Peterffy
https://en.wikipedia.org/wiki/Thomas_Peterffy
Interactive Brokers Group, Inc. (IB) is an online discount brokerage firm in the United States. The company traces its origin to 1977 when Peterffy bought a seat on the American Stock Exchange as an individual market maker, and formed T.P. & Co. the following year. IB consists of many subsidiaries operating on most major stock, futures,bonds, forex, and options exchanges worldwide.
OneChicago[edit]
Main article: OneChicago
OneChicago is an all-electronic exchange owned jointly by IB Exchange Group (IB), Chicago Board Options Exchange (CBOE), and CME Group. It is a privately held company that is regulated by both the Securities and Exchange Commission and the Commodity Futures Trading Commission.
Boston Options Exchange[edit]
Main article: Boston Options Exchange
Peterffy was involved in the founding of the Boston Options Exchange (BOX). BOX is an automated stock exchange owned and operated by the TMX Group. As an equity options market, it provides electronic order matching services to stockbrokers and traders.
