Iceberg order

An iceberg order is a limit order that displays only a fraction of its total quantity in the order book and automatically replenishes the displayed part as it trades. From the outside it looks like a level that keeps refilling at the same price after each execution; aggregated depth alone cannot distinguish it from several independent orders.

Senzoukria · Glossary · Updated September 2026

Mechanics

Exchanges and brokers offer order types that expose a display quantity smaller than the order's full size. When the displayed part is filled, the matching engine reveals the next slice at the same price. The book therefore shows a modest number that keeps coming back after each execution, while the total quantity behind it stays hidden. The purpose is to trade a large size without advertising it, which is why iceberg detection interests orderflow readers.

  • Displayed slice: the visible part of the order at any instant.
  • Reserve: the remaining hidden quantity, unknown to other participants.
  • Refill: the moment a new slice appears after the previous one traded.

What the screen actually shows

On a heatmap, an iceberg is consistent with a band that stays bright while trade dots accumulate on it. On a footprint, the same event appears as executed volume at one price that exceeds the size ever displayed there. Consider the hypothetical example used in the heatmap guide on this site: 120 contracts displayed at one ask price, 80 contracts trade there during the next interval, and 100 remain displayed. If coverage is complete, these totals are consistent with net additions of 60 contracts. They do not identify a single hidden order, because cancellations, new orders from other participants and a native iceberg can all produce the same totals.

How to investigate a suspected iceberg

  • Match executions to book changes at the same price and time; a refill that follows each fill within the same update is more suggestive than one that arrives seconds later.
  • Count the refills. One refill is ordinary; a series at the same price while price is pinned is the pattern worth recording.
  • Note whether price stalled or continued after the refills, and keep the counterexamples.
  • Order-level data (MBO) adds detail on order lifetimes, but the fields the feed exposes decide what can be established; participant identity is never one of them.

In Senzoukria

The Heatmap screen has an Iceberg rings marker, described in the settings as showing where someone keeps refilling the same level out of sight, and a Refills to call it an iceberg threshold; the hint suggests two refills suits a liquid index future and a lower value a quiet contract. In the Liquidity lens panel a repeated refill appears as a Refill candidate, and its notes state that aggregated depth changes do not identify individual orders and that even observed MBO refreshes do not confirm a native iceberg. The Volume / traded range study in the indicator library carries an explicit note that its heuristic does not prove passive replenishment or iceberg orders.

Common mistakes

  • Declaring an iceberg from one refill. Market makers requote constantly, and a single reappearance proves nothing.
  • Assuming an iceberg belongs to one participant with one intention. Several orders can share a price.
  • Trading against a detected iceberg without a stop, as if hidden size could not be exhausted.

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Frequently asked questions

Can an iceberg order be detected from trade data alone?
Only partially. A footprint can show executed volume at a price that exceeds any size ever displayed there, which is consistent with hidden replenishment. Confirming the refills requires the book updates at that price and time; trade prints by themselves do not show when the displayed size came back.
Is an iceberg the same as absorption?
They overlap but are not identical. Absorption describes aggressive volume trading into a level without moving price. An iceberg is one mechanism that can produce absorption, but a level can also absorb through many independent limit orders arriving as others are filled, and an iceberg can be exhausted, after which price moves through.
Do crypto exchanges support iceberg orders?
Some venues offer order types with a hidden or display quantity; the details differ by exchange and market type. On a crypto heatmap built from aggregated depth, the refill pattern looks the same as on futures, and the same caution applies: the display cannot tell a native iceberg from several orders at one price.

Keep reading

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