Reserve/Iceberg

Large orders are frequently divided into smaller parts, whether using an algorithm or not, so that the public market displays only a small portion of the order at a time. The analogy being the 'tip of the iceberg' as the only visible portion of a huge mass of ice. By hiding its large size, the iceberg order reduces the price movements caused by substantial changes in a stock's supply and demand. Some exchanges accommodate iceberg, reserve or hidden orders.