Orders with the Hidden flag will not be shown in the Everstrike Order Book. This disguises your intentions, and is best used for large orders that are likely to cause significant market impact.
Without the Hidden flag, a large order could potentially influence other traders and drive the price in a direction that is not in your favour.
With the Hidden flag, the market impact of the order is close to non-existent.
If you do not want to hide the entire order, you may instead use a number of Icebergs. The order quantity shown will then be determined by the following formula:
Quantity shown = Order quantity / # icebergs
In other words, if you choose 10 Icebergs, 90 percent of your order quantity will be hidden.