The market system in EVE Online operates on a brokerage system and the concept of "Sell Orders" and "Buy Orders". This means, all requests will be either a buy or sell order that is going through a broker, even if they are to be fulfilled immediately, and a player will have no control over which orders will be chosen by the broker system to fulfill their requests.
The market will guarantee that players receive or sell the requested item for the price they have specified if the request can be fulfilled immediately, or possibly for a better price if no immediate fulfillment is possible and the order gets listed on the market.
The market differentiates between buy orders and sell orders. They are functionally identical with the main difference being that buy orders are waiting to buy something and sell orders are waiting to sell something respectively. A buy order asks for an item to be provided within the range set on the buy order and offers money, while a sell order asks for money and offers an item, which will be sold at the station the sell order was created. Only repackaged (stackable) items can be sold on the market. Assembled Ships or modules and used blueprint originals or blueprint copies can not be traded through the market.
Market Order matching
As described above, the broker system will try to match buy and sell orders immediately at every creation or change of an order by the following rules, before (re)listing the respective order on the market:
- Sell order creation/change:
Of the listed buy orders that have the range to take the item of the sell order and offer at least the asking price of the sell order, the buy order with the highest price will receive the items at the price the seller offered. If the number of items in the sell order is more than what the buy order wants, the next highest buy order will receive the remainder of the sell order. This is repeated until the number of items the sell order is exhausted and thus the sell order completed. Only if there is no further buy order available to take the remaining amount of the sell order, the sell order will be listed on the market.
- Buy order creation/change:
Of the listed sell orders offering the item at the offer price of the buy order or lower, the sell order with the lowest price will be fulfilling the buy order and the seller will receive the price per unit offered by the buy order. Should the buy order want more items than the sell order can deliver, the process will be repeated for the next lowest sell order until the buy order has been filled. Only if there is no further sell order that can fill the remaining demand of the buy order at the offered price, the buy order will be listed on the market.