Iceberg Order
An iceberg order is a large order that shows only a small part in the order book at a time, hiding its true size; such hidden liquidity can absorb big moves.
An iceberg order is a large limit order that shows only a small part of its size in the order book. When that visible part fills, the next part appears. Traders use icebergs to hide how much they really want to buy or sell.
- Category
- Market Structure
- Reading time
- 3 min
- Also called
- Reserve order, Hidden-size order
- Updated
An iceberg order in plain words
Iceberg orders let traders place a large order without showing its full size to the market.1
Some exchanges call them reserve orders: only part of the total is ever displayed.2
In short, it is a limit order where other traders see just a slice of the real size.3
How an iceberg order works
Set the terms
Set three things: the limit price, the total size and the visible “peak”.1
Show the peak
Only the peak appears in the book.
Fill the peak
Other traders trade against the visible part.
Refresh
When the visible peak fills and hidden size remains, a fresh peak appears in the book with a new timestamp.1
Respect minimums
Check venue minimums — on one bond platform, at least 5% of the total must be visible.1
Finish
The order ends when the total volume fills or is cancelled.
Worked examples
Example 1 — Peaks
20 peaksHypothetical total 10,000, peak 500.
| Refreshes | 10,000 ÷ 500 = 20 peaks |
Each time the visible slice filled, a new one appeared with a fresh timestamp until the order was done.1
Example 2 — Minimum display
2,000 shownHypothetical total 40,000 on a venue with a 5% rule.
| Minimum peak | 2,000 |
The venue required at least 5% of the order to be visible, which set the size of each slice.1
Example 3 — Spotting one
Likely icebergA hypothetical bid at 50.00 keeps showing 300 after many fills.
| Traded | 6,000 at 50.00 |
The level kept refilling after each fill — a sign of a much bigger hidden order.2
Iceberg vs plain limit order
| Aspect | Iceberg order | Limit order |
|---|---|---|
| Size shown | Peak only | Full size |
| Queue priority | Lost on each refresh | Kept |
| Impact | Lower signal | Higher signal |
| Availability | Venue-dependent | Everywhere |
Where icebergs are used
Large orders
Hiding size in the Order Book.
Order flow
Reading hidden supply in Order Flow.
Levels
Defending Support and Resistance.
Execution
Reducing Slippage on big trades.
Advantages and disadvantages
Advantages
- Hides true order size.
- Reduces market impact.
- Executes automatically in pieces.
Disadvantages
- Loses time priority on each refresh.
- Can be detected by watchers.
- Not offered by every venue or broker.
- Fills may be slower.
Going deeper
Read as far as you need. Each level builds on the one before it.
Purpose
Beginner
The point is to work a large order without tipping off the market.1
Time priority
Intermediate
Each refill gets a new timestamp, so it joins the back of the queue at that price.1
Venue rules
Advanced
Every iceberg has a limit price, a total size and a visible peak; the minimum peak and other rules vary by venue.1
Common mistakes
Peak too small
Very small peaks are easy to spot.
Ignoring priority
Each refresh loses queue place.
Assuming every bid is real size
Some size is hidden.
Using where unsupported
Check your broker.
Check your understanding
Test yourself before moving on. Each answer comes with an explanation.
Key points to remember
- Icebergs show only part of their size.
- They are limit orders with a peak.
- Each refill loses time priority.
- Venues set their own rules.
- Repeated refills can reveal them.
Frequently asked questions
Can retail traders use iceberg orders?
Are icebergs legal?
How do I detect one?
Further learning
- Limit Order
The base order type.
- Order Book
Where peaks appear.
- Order Flow
Spotting icebergs.
- Slippage
Cost of big trades.
Sources
This article is written in our own words. The sources below support the specific facts, rules and figures marked with a number in the text. Links open the original publisher’s page.
- Eurex Bonds. Eurex Bonds Market Model (opens in a new tab) Checked .
- Nasdaq. Nasdaq Order Types (opens in a new tab) Checked .
- Bookmap. Glossary – Bookmap Knowledge Base (opens in a new tab) Checked .
Educational content, not financial advice. Examples use hypothetical prices and simplified costs; actual fees, margin rules and regulations vary by broker, market and country. We are not affiliated with any publisher linked above. Last reviewed . Report an error or request a source credit.