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. The company commenced a public offering on 4 May 2007 under the ticker symbol NASDAQ: IBKR on the Nasdaq exchange. Barron's Magazine stated in 2009 that Interactive Brokers maintains a position as "the least expensive trading venue for investors", and has held the ranking as the lowest cost broker for five straight years. An analysis of their on-line website, however, indicates many higher charges than traditional brokers (e.g., borrow rates based on security prices rounded up to the nearest dollar, as opposed to industry standard of just 102% or price, etc.)