TL;DRThe Depth of Market display showing resting limit orders at every price level. It reveals where buyers and sellers are waiting, how much size is stacked at key levels, and how liquidity is distributed around the current price.
The DOM (Depth of Market), also called the order book or ladder, is a real-time display of all resting limit orders at each price level near the current market price. It shows how many contracts are available to buy (bids) and sell (offers/asks) at each price.
The DOM is the market's supply and demand in raw form. If there are 500 contracts on the bid at 5,200 and only 50 on the offer at 5,200.25, you can see the imbalance directly. This information is invisible on a standard price chart.
The center of the DOM shows the current bid and ask prices. Above the current price, you see resting sell limit orders (offers). Below, you see resting buy limit orders (bids).
Large orders at a specific level can act as support or resistance. If 2,000 contracts are sitting on the bid at 5,195, many traders expect that level to hold because it would take significant selling to work through that size.
The rate at which contracts are being added or pulled at each level tells you about participant intent. Size that keeps refreshing (gets hit and immediately replenishes) suggests a genuine institutional level. Size that gets pulled as price approaches is likely a bluff (spoofing, which is illegal but still occurs).
DOM-based trading (also called tape reading or order flow trading) involves watching the real-time interaction between aggressive market orders and passive limit orders to gauge short-term direction.
When aggressive buyers consistently lift offers (buy at the ask) and the ask-side depth is thinning, price is likely to move up. When aggressive sellers consistently hit bids and bid-side depth is thinning, price is likely to move down.
This is the most granular form of analysis and is primarily used by scalpers trading on very short timeframes (seconds to minutes). It requires significant screen time and practice to develop proficiency.
Reading large resting orders
The DOM shows 1,500 contracts on the bid at 5,200 on ES, compared to 200-300 at surrounding levels.
This size at 5,200 suggests an institutional buyer or algo defending that level. Price may bounce off 5,200 multiple times. If the 1,500 contracts finally get absorbed (filled through), the level breaks and price may accelerate lower as protective orders behind it get triggered.
Absorption on the DOM
ES is sitting at 5,205 offer. 800 contracts are on the offer. Aggressive buyers keep hitting the offer, volume goes through, but the 800 keeps refreshing.
This is absorption. A large seller is feeding contracts at 5,205, absorbing all buying pressure. This often means price will not break above 5,205 until the seller is finished. Scalpers may look to short near this level.
Thinking large resting orders always hold
Large orders can be pulled (canceled) in milliseconds. Treat DOM size as probabilistic, not definitive. Size that holds under pressure is real. Size that disappears as price approaches is not.
Trading DOM in isolation without price context
The DOM shows what's happening right now, but without knowledge of where you are in the day's range, value area, and trend, DOM signals are easily misinterpreted.
Trying to learn DOM trading before mastering basic order types and market structure
DOM reading is an advanced skill. Learn how orders work, understand market structure (support/resistance, value areas), and then layer DOM reading on top.