In terms of volume, Interactive Brokers is technically the largest online stock trading platform in the U.S. It also advertises itself as the “lowest cost broker,” and for good reason: It only charges a startlingly low $0.005 per trade on stocks, ETFs, options, bonds, mutual funds, and futures (plus a 7 cent per contract fee for options). Technically, that’s still higher than Robinhood, but Robinhood only offers stocks, ETFs, and options (and as we noted above, Robinhood does skim some money off the top of trades via “payment for order flow”).
Each publicly traded company lists their shares on a stock exchange. The two largest exchanges in the world are the New York Stock Exchange (NYSE) and the NASDAQ; both are based in the United States (Wikipedia). Attempting to grasp just how large the NYSE and NASDAQ both are is certainly not easy. The NYSE has a market cap of nearly $31 trillion and the NASDAQ’s is nearly $11 trillion. And yes, that is not a typo, I said, “trillion”.
A few decades ago, most buyers and sellers were individual investors, such as wealthy businessmen, usually with long family histories to particular corporations. Over time, markets have become more "institutionalized"; buyers and sellers are largely institutions (e.g., pension funds, insurance companies, mutual funds, index funds, exchange-traded funds, hedge funds, investor groups, banks and various other financial institutions).
New York Stock Exchange NASDAQ London Stock Exchange Japan Exchange Group – Tokyo Shanghai Hong Kong Euronext Shenzhen Toronto Stock Exchange Deutsche Börse Bombay Stock Exchange National Stock Exchange of India SIX Swiss Exchange Australian Securities Exchange Korea Exchange NASDAQ OMX Nordic Exchange JSE Limited BME Spanish Exchanges Taiwan Stock Exchange B3 Singapore Exchange Moscow Exchange Stock Exchange of Thailand Tadawul Indonesia Stock Exchange
The New York Stock Exchange (NYSE) is a physical exchange, with a hybrid market for placing orders electronically from any location as well as on the trading floor. Orders executed on the trading floor enter by way of exchange members and flow down to a floor broker, who submits the order electronically to the floor trading post for the Designated Market Maker ("DMM") for that stock to trade the order. The DMM's job is to maintain a two-sided market, making orders to buy and sell the security when there are no other buyers or sellers. If a spread exists, no trade immediately takes place – in this case the DMM may use their own resources (money or stock) to close the difference. Once a trade has been made, the details are reported on the "tape" and sent back to the brokerage firm, which then notifies the investor who placed the order. Computers play an important role, especially for program trading.