A parallel concept to All or None (AON) and Fill Or Kill (FOK) Orders where assets must be sold in small amounts.
An iceberg order is any market order that was originally large but was restructured to be sold in specific but smaller quantities. The point behind this decision is to ensure that the total size of the original order is hidden from prying eyes, with only the fractions available for purchase. Thus, an iceberg order is also known as a reserve order and is typically used by traders and investors with a lot of trading power.
Compared to AONs and FOKs, iceberg orders are not ultimately intended to directly boost trader profit. Instead, traders use them to get rid of assets and shares without disrupting the market.