Level 2 market data, often presented in a format displaying the order book, provides a real-time window into the depth and breadth of buy and sell orders for a particular security at various price levels. It shows the best bid and ask prices (the inside market) along with the volume of shares available at each price point from different market participants, such as market makers and electronic communication networks (ECNs). For example, if a stock is trading at $50, Level 2 data will show how many shares are offered for sale at $50.01, $50.02, and so on, as well as how many shares are being bid for at $49.99, $49.98, and so forth.
Understanding this data offers a more granular view of supply and demand compared to Level 1 data, which only displays the best bid and ask prices and the latest trade. It can potentially offer insights into short-term price movements, identify potential support and resistance levels, and gauge the overall sentiment towards a security. Access to this more detailed information became increasingly important with the rise of electronic trading and direct market access, allowing traders to make more informed decisions based on the actual order book dynamics.
