Abstract: Preferred embodiments of the subject invention comprise the steps of: (a) electronically receiving first participant information, said first participant information including a first order having a first price and a first size; (b) electronically receiving a second order having a second price and a second size from a second participant; (c) executing said second order against said first order if said first price matches said second price and said first size matches said second size, and if said first participant information indicates that said first order is exposed to immediate matching against incoming orders; and (d) executing randomly-timed match check events wherein other orders are matched against the first order if said first price and said first size match prices and sizes of said other orders and if said first participant information indicates that said first order is to be exposed to randomly-timed match check events.

Abstract: Preferred embodiments of the subject invention overcome the limitations of known trading interest dissemination and execution systems by (1) enabling market participants to limit dissemination of trading interests to only those other market participants likely to have a significant contra-interest, (2) enabling market participants to ensure that other market participants' disseminated trading interests are legitimate, and (3) enabling auctions among trading interests targeted and validated in this manner. Software of a preferred embodiment identifies likely contra-interests by analyzing information from various sources regarding certified trading interests.

Abstract: The subject invention overcomes the limitations of known market data displays by producing a graphical market display that integrates analysis of both 1) intra-day trading activity by classes of market participant, and 2) projected market impact as a function of trade size give the present set of executable orders in an electronic securities trade execution network. In a preferred embodiment, the display is used as the graphic user interface (GUI) of an ECN. In alternate preferred embodiments, the display is offered by a market data analysis service that accesses information form one or more ECNs, exchanges, or stock market. In another alternate embodiment, the display is created by software on a user computer form liquidity information already on that user computer.