What Is Market-By-Order (MBO) Data? A Trader's Guide to Level-3 Order Flow

Most retail charting platforms show you a candle: open, high, low, close. That candle is the *summary* of thousands of individual decisions — every order placed, modified, and cancelled during that period, compressed into four numbers. Market-By-Order (MBO) data is what's underneath the summary.

What Market-By-Order Data Actually Is

MBO is the most granular level of market data an exchange publishes. Instead of a snapshot of the best bid/ask (Level 1) or the aggregated size sitting at each price level (Level 2), MBO gives you every discrete order event as it happens — a new order added to the book, an existing order's size reduced, an order cancelled outright, or an order matched against incoming flow.

Because every event carries a timestamp and a price, reconstructing the full order book from MBO data lets you see things a candle simply cannot show: how fast size is being added or pulled at a specific price, whether a large order got filled in one print or worked quietly over dozens of smaller ones, and where the book is thin enough that a moderate order could move price on its own.

MBO vs. Level 1 vs. Level 2

FeedWhat you seeUpdate granularity
Level 1Best bid, best ask, last tradeTop of book only
Level 2Aggregated size at each price levelPer price level
Level 3 / MBOEvery individual order event (add, modify, cancel, fill)Per order

Level 1 tells you the price. Level 2 tells you how much size is stacked nearby. MBO tells you the *behavior* behind that size — whether it's building, being defended, or being pulled the moment price approaches it.

CVD by Lot Size, Not by Guessing Who's Trading

A common mistake when working with order-flow data is trying to label *who* placed an order — "that's an institution," "that's a retail trader." Exchanges don't publish participant identity, and no feed can prove it reliably from order data alone. What MBO *does* let you measure honestly is order size.

Cumulative Volume Delta (CVD) tracked by observed lot size — commonly bucketed into small, medium, large, and whale tiers — tells you how buying and selling pressure is distributed across order sizes over time, without pretending to know the identity of the trader behind any single print. That distinction matters: it's the difference between a measurable signal and a marketing claim.

Absorption Walls and Liquidity Sweeps

Two patterns come up constantly in MBO-based order-flow analysis:

  • Absorption — price presses repeatedly into a price level and large resting size keeps refilling instead of breaking, effectively "absorbing" the incoming aggression. This is visible in MBO as a wall that keeps replenishing after fills, something Level 2 alone will only show as size that doesn't move.
  • Liquidity sweep — the opposite: resting size at a level gets pulled or aggressively taken out in a short window, and price moves through it cleanly. MBO shows this as a fast sequence of cancels and fills at the same price, distinguishable from a slow, orderly fade.

Neither pattern is visible on a standard candle chart. Both are routine to spot once you're watching order-level events instead of an aggregated snapshot.

How ATLAS Uses This Data

ATLAS Sovereign ingests CME Gold (GC) order flow at MBO Level-3 depth and runs it through whale-tier CVD classification and absorption-wall detection as two of its five confluence pillars — see the pricing and feature breakdown for the full list. As with any order-flow methodology, this is one input among several, not a standalone prediction; trading involves substantial risk and past patterns do not guarantee future results.


*Have a term you'd like explained — OBI, footprint, POC/VAH/VAL? Contact support and we'll cover it in a future post.*

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