What Is Level 2 (L2) Data?
Level 1 data shows the best bid and best ask plus last-trade information — what retail traders typically see for free. Level 2 (also called L2 or depth-of-book) shows all visible limit orders at every price level, both sides of the book, in real time.
L2 reveals where supply and demand sit. Large bids stacked at $99.50 act as visible support; large asks at $101.25 indicate resistance. Watching how orders appear, get filled, and disappear gives a sense of who's pushing the market — though spoofing (placing orders intended to be cancelled) is a real complication.
L2 access is paid on most platforms: $5-30/month per exchange feed. For day traders and scalpers, L2 is often essential. For swing or position traders, the marginal value is low — the patterns over hours don't depend on millisecond order-book dynamics.
Related terms
- Order Book — Real-time list of all open buy and sell orders for an asset, by price.
- Bid-Ask Spread — The gap between the highest price buyers will pay (bid) and the lowest price sellers will accept (ask).
- Liquidity — The ease with which an asset can be bought or sold without significantly affecting its price.
- Market Maker — Firm that quotes both buy and sell prices, providing liquidity for a profit on the spread.