I see that US value bundle (one of the IB's market data product) has following description : " A BBO alternative that will deliver aggregated quote, trade, volume, and optional depth information for all four US equity exchange books operated by BATS (BATS, BYX, EDGX, EDGEA). Includes Dow Jones Industrial Average and S&P 500 Indices and top of book GLOBEX quotes for CBOT, CME, COMEX, and NYMEX" Can someone explain me what are these different exchanges? I am aware of NYSE and NASDAQ. Would this data contain real-time information from the companies listed at NYSE and NASDAQ? How does it work?