What Is a “Reserve Order” and How Is It Similar to an Iceberg Order?

A reserve order is an electronic order type that allows a trader to display only a portion of their total order quantity, keeping the remainder "in reserve" or hidden. This visible portion is automatically refreshed from the reserve quantity as it is filled.

It is essentially another name for an iceberg order, designed to mask the true size of a large trade to minimize its price impact and potential slippage on the market. Both are passive order types.