Actually, Nasdaq makes more money on licensing its data than on the rest of its businesses. You can go to each exchange and buy the historical data directly. Ge

Actually, Nasdaq makes more money on licensing its data than on the rest of its businesses. You can go to each exchange and buy the historical data directly. Generally, this is better for backdating depth of book data than say a Bloomberg in my experience but requires a lot more upfront work (parsing, normalizing). Additionally, any non-hft trader that handles institutional trading needs to pay a small fee (roughly $20/month per exchange) in each system that requires real-time data. Also, little-known fact, no retail trading orders hit the actual exchange. Even institutional investors who are not brokers (like most hedge funds) must execute through a broker/EMS.