Book imbalance

Book imbalance is the ratio of resting buy quantity to resting sell quantity, usually measured over the top few price levels. Many automated strategies key off it directly, which is what makes a manufactured imbalance profitable.

market microstructure · updated 2026-09-08

Where does book imbalance come up?

This term is used in the following manipulation techniques, each explained in full on its own page.

• Spoofing — Spoofing is placing orders a trader intends to cancel before execution, to create a false impression of supply or demand and move the price toward a smaller genuine order on the other side.
• Layering — Layering is placing multiple orders at several consecutive price levels with no intention of trading them, building an apparent wall of depth that pushes the price toward a genuine order on the other side.
• Momentum ignition — Momentum ignition is entering a burst of aggressive orders designed to trigger other participants' momentum strategies, creating a price move the initiator then trades against.

Enforcement actions involving these techniques

See also

• Depth — Depth is the total quantity available at each price level in the order book. Deep books absorb large orders with little price move…
• Order book — The order book is the live list of all outstanding buy and sell orders for an instrument, arranged by price, that a trading venue …

Terms that refer here

Momentum ignition

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