Abstract: Computer network apparatus for supporting open market trading is disclosed. The apparatus includes a) a database storing sellers' Asks and buyers' Bids, b) a means for receiving from a buyer or a seller an order to buy or sell a subject product, and c) filters for parsing sets of Bids and Asks stored in the database. A Commodity Filter parses based on user-specified attributes of products (Commodities). A Quantity Filter aggregates and filters the quantities of sets of the product. As such, customized screen views for the subject Class of product are displayed and enhance trading on the same. A match engine completes a transaction when an order is found to match a stored Bid or Ask. A participant enhancer notifies otherwise dormant buyers and sellers of the current displayed market and trading.