Bookmap Order Book (DOM) Basics
The Bookmap order book DOM columns show you the raw depth of market: how many contracts are sitting at each price level, how that liquidity changes, and where trades are actually hitting. The heatmap and bubbles give you the picture; the DOM columns give you the numbers behind it.
What the Bookmap DOM Columns Show
Depending on your layout, you’ll see several vertical columns next to price. Common ones include:
- Bid size – resting buy limit orders at each price
- Ask size – resting sell limit orders at each price
- Cumulative depth – running total of size above or below price
- Recent trades – last executed volume at that level
- Imbalance – difference between bid and ask size
You’re basically looking at the ladder, but with more context and better visualization than a classic DOM.
Bid and Ask Size Columns
These are the foundation. They tell you how much liquidity is sitting at each price.
| Side | Meaning |
|---|---|
| Bid size | Buy limit orders waiting to be hit |
| Ask size | Sell limit orders waiting to be lifted |
Heavy size on the bid below price can act like temporary support. Heavy size on the ask above price can act like temporary resistance.
If you’re not clear on what Bookmap is doing overall, read this first: Bookmap Basics: What It Is and How It Works.
Cumulative Depth Columns
Cumulative depth adds up the size across multiple price levels on either side of current price. It shows how “thick” or “thin” the book is.
- Thick book = lots of resting orders = harder to move
- Thin book = light resting orders = easier to push through
This helps you see if the market is about to rip through air or slam into a wall of orders.
Recent Trades Column
This column shows where trades have just executed and how big they were. It works together with the volume bubbles on the chart.
- Big prints at the bid = aggressive sellers
- Big prints at the ask = aggressive buyers
When you match recent trades in the DOM with bubbles on your chart, you can see exactly where aggression hit and whether it moved price or got absorbed.
Imbalance Columns
Imbalance columns compare bid and ask size at each level.
- Bid >> Ask = buy-side heavy
- Ask >> Bid = sell-side heavy
Large imbalances can flag one-sided liquidity. Sometimes that’s real interest. Sometimes it’s bait.
DOM Behavior That Actually Matters
1. Liquidity Stacking
When you see size piling up repeatedly at the same price, that’s stacking. It often marks:
- A level big players want to defend
- A magnet where price is likely to trade
2. Liquidity Pulling Before Price Hits
Size disappears right before price reaches that level. That usually means:
- Spoofing (fake orders)
- Traders cancelling interest as price approaches
- Potential breakout or fast move through that level
3. Chasing Liquidity
When large orders move up or down with price, they’re “chasing.” That often signals:
- Momentum continuation
- Market makers adjusting quickly
- Participants trying not to get left behind
DOM + Heatmap + Bubbles = Full Picture
The DOM columns should not be used in isolation. They’re part of the Bookmap triad:
- Heatmap – where liquidity rests
- Volume bubbles – where trades hit
- DOM columns – the numbers behind both
When all three align, you’re seeing the actual battle between buyers and sellers, not just candles.
Common Mistakes Reading the DOM
- Taking every large order at face value (some are spoofed)
- Ignoring how often size appears and disappears
- Staring at every tiny size change instead of big shifts
- Forgetting that real intent is confirmed by executed trades, not just resting orders
The DOM is signal and noise at the same time. Your job is to focus on size that stays, moves with purpose, or gets hit hard.
Final Thoughts
The Bookmap order book DOM columns show you raw depth, size shifts, and recent trade locations. Combined with the heatmap and volume bubbles, they give you a full picture of where liquidity sits, who is attacking it, and whether those attacks succeed. Learn to watch size that stays vs size that runs, and you’ll stop trading blind against big players.