Level 2 Data (also known as 'Market Depth') is a trading screen that shows you the “order book” for a particular stock. Think of standard stock quotes (Level 1 Data) as seeing only the highest price a buyer is willing to pay and the lowest price a seller is willing to accept right now. Level 2 data pulls back the curtain, revealing a ranked list of all the individual buy and sell orders waiting to be executed. It shows you not just the best prices, but the second-best, third-best, and so on, along with the number of shares being bid for or offered at each price level. This gives you a much richer, real-time view of a stock's supply and demand dynamics, moving beyond a simple price quote to show the depth of buying and selling interest.
A Level 2 screen is typically split into two sides: the buy side (bids) and the sell side (asks).
Imagine you're looking at Level 2 for Company XYZ. It might look something like this: Bids (Buyers)
Asks (Sellers)
In this snapshot, the bid-ask spread is just one cent ($10.00 vs $10.01). More importantly, you can see a large block of 2,000 shares waiting to be bought at $9.98, which might act as a short-term price “floor” or support level.
While often seen as a tool for high-frequency traders, Level 2 data can offer valuable context for the patient value investor, especially when timing an entry or exit point for a fundamentally sound company.
The “thickness” of the order book tells you about a stock's liquidity. A deep book with many orders on both sides means you can likely buy or sell a significant number of shares without drastically affecting the price. A “thin” book means the price could be volatile. Furthermore, a heavy imbalance—say, far more buy orders than sell orders—can signal strong short-term bullish market sentiment. A value investor might use this to confirm that others are also beginning to see the value they've identified through their research.
Occasionally, you'll see an unusually large order on the bid or ask side.
For a value investor who has decided to buy a company at, say, $50, seeing a large buy wall at $49.50 might provide the confidence to place their order, knowing there's significant short-term support.
Level 2 is a powerful tool, but it's not a crystal ball. It can be—and often is—manipulated.
A major caveat is a practice called spoofing, where traders place large orders with no intention of letting them execute. For example, a manipulator might place a huge sell wall to create the illusion of heavy selling pressure, spooking other investors into selling. Just as the price drops, the spoofer cancels their massive sell order and buys the stock on the cheap from the panicked sellers. The key takeaway is: Never make a decision based on Level 2 data alone. It should only serve as a supplement to your core value investing principles.
The other big secret is that Level 2 doesn't show you everything. A significant amount of trading volume, especially from large institutions, happens off the public exchanges in so-called dark pools. Institutions do this to buy or sell massive positions without tipping off the market and causing the price to move against them. So, that “buy wall” you see might be insignificant compared to a huge institutional sell order lurking unseen in a dark pool.
To put it simply:
(There is also Level 3 data, but it's primarily for registered brokers and market makers, granting them the ability to enter and change quotes, so it's not something the average investor needs to worry about).