An iceberg order is a large order that shows the market only its tip. An institution wanting to buy 5 lakh shares doesn't place one visible order — it would move the price against itself instantly. Instead it displays 5,000 at a time, automatically reloading each slice as it fills. The visible order book never looks unusual; the tape tells a different story.
Size is information. A visible 5-lakh-share bid tells every other participant that a big buyer is here — and prices adjust before the buyer finishes. Icebergs solve this: the exchange holds the full order, displays a small visible slice, and replenishes it as fills happen. The institution gets its size done near one price; the market sees only ripples.
This matters to you because iceberg activity marks prices that large players consider worth defending — and those levels keep mattering after the iceberg is done.
You cannot see an iceberg in the order book — that is its whole point. You see it in the relationship between traded volume and price movement. The classic signature: the DOM shows a modest resting order at a level, yet the tape prints fill after fill at that price and the displayed size never shrinks. Ten times the visible quantity trades there, and the level still holds.
On a footprint chart this appears as a price level accumulating extraordinary volume while price refuses to move through it — closely related to absorption, but concentrated at one reloading level rather than spread across a zone.
Iceberg levels tend to keep their significance. A price where someone silently accumulated lakhs of shares is a price they have an interest in; when the market returns there, the same participant is often still around. Practically: note levels where volume massively out-printed the visible book, and watch how order flow behaves on a revisit — repeated defence tells you the interest is still alive, a clean cut through it tells you it's gone.
Yes — NSE supports disclosed-quantity orders, where you show only part of your total quantity. Brokers expose this as the "disclosed qty" field. The mechanics are the same idea institutions use, at smaller scale.
Absorption is the broad phenomenon — aggressive volume being soaked up without price movement, possibly by many passive orders across a zone. An iceberg is one specific mechanism: a single reloading order at one price. Icebergs cause absorption; not all absorption is an iceberg.
Heuristically, yes: when traded volume at a price repeatedly exceeds the displayed size that was resting there, a reloading order is the likely explanation. VolumeLens surfaces this through big-trade detection and per-level footprint volume rather than a labelled "iceberg" flag — the data shows the signature, the interpretation stays with the trader.
Both. Any instrument with a live order book can host disclosed-quantity orders. They are most consequential on liquid names and index futures, where institutional size actually needs hiding.