The DOM is a price ladder: one row per price, with resting bid size on the left, the price in the center, and resting ask size on the right. Above the ladder, a quote strip shows the best bid, the best ask, and the spread. Reading it well is mostly a matter of knowing what the sizes represent, how price grouping changes what you see, and how the ladder decides which prices to keep on screen. The DOM needs market-depth access for the selected instrument; if quotes or a whole side show dashes, check your Level 1 and depth access first.
The last-trade marker identifies the bucket that contains the most recent trade, so you can see where activity is landing relative to the inside market. Depth changes alone do not prove a trade occurred — use Time & Sales when you need confirmed executions.
Bid and ask quantities represent reported resting interest. The background bars behind each row scale against the largest quantity currently displayed, which makes relative size easy to compare at a glance. Futures sizes stay in whole contracts; supported perpetual products convert lots using the instrument's size decimals.
Displayed liquidity is a snapshot, not a commitment. It can change or disappear at any moment, it excludes hidden orders, and it reveals neither intent nor your queue position at a price.
Use minus for wider steps and plus for finer steps. The label shows the current multiplier, such as 1× tick. Wider grouping combines native exchange levels into displayed buckets, which is useful for seeing structure across a range but hides how size is distributed inside each bucket. Grouping only changes presentation — it does not change exchange prices. Return to 1× tick before you select an exact native level.
By default the ladder follows the live market. Scroll vertically to inspect another price area and the control changes from Following to Recenter. Select Recenter to jump back near the live midpoint and resume following. If the inside market seems to be missing entirely, select Recenter and return to 1× tick before assuming a data problem.
