Abstract: A computer-implemented method and apparatus for releasing a data item having an identifier for transaction processing in a data transaction processing system in which data items are transacted by a hardware matching processor that matches electronic data transaction request messages for the same one of the data items based on multiple transaction matching parameters from client computers over a data communication bus. A restriction on the hardware matching processor from processing electronic data transaction request messages for the data item is detected. A hardware data processor determines a variability in one of the transaction matching parameters for the data item. The determined variability is compared to a variability threshold established for the data item, and an adjusted one transaction matching parameter of the data item is calculated based on the determined variability.

Abstract: Amongst other things, a computer implemented method for releasing a security for trading in a trading venue includes determining volatility in prices of quotations for a security before the security is released for trading; comparing the determined volatility to a volatility threshold; calculating an adjusted price of the quotations based on the output of the determined volatility in the prices; sending a message to release the security for trading, with the security having the adjusted price that is based on the outcome of comparing.

Abstract: A method for trading a security in an electronic market includes entering an order at a client station for executing against any market participant that can at least in part satisfy the order, and matching the entered order at a server system against interest in the market based on how the market participant participates in the market with a portion of the interest in the market being prioritized according to price priority among displayed quotes/orders of market makers, ECNs that do not charge a separate quote-access fee, and non-attributable agency orders of UTP Exchanges, and subsequently by displayed quotes/orders of ECNs that charge a separate quote-access fee, with the quotes/orders of the ECNs that charge a separate quote-access fee being ranked by the amount of the quote-access fee charged.

Abstract: Amongst other things, a computer implemented method for releasing a security for trading in a trading venue includes determining volatility in prices of quotations for a security before the security is released for trading; comparing the determined volatility to a volatility threshold; calculating an adjusted price of the quotations based on the output of the determined volatility in the prices; sending a message to release the security for trading, with the security having the adjusted price that is based on the outcome of comparing

Abstract: A method, executed in a computer system, for opening an electronic market for trading of a security is described. The method includes receiving by the computer system eligible orders and quotes for the security traded in the electronic market and disseminating an order imbalance indicator indicative of predicted trading characteristics of the security at the open of trading. The method also includes determining by the computer system a price or prices at which the maximum shares would be executed and determining which price would minimize any imbalance of eligible orders and executing at least some of the eligible orders at the determined opening price.

Abstract: A method for trading a security in an electronic market includes receiving closing orders and orders for the security traded in the electronic market, disseminating an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading, determining a closing price for the security based on the closing orders and orders, and executing at least some of the closing orders at the determined closing price.

Abstract: A method for trading a security in an electronic market includes entering an order at a client station for executing against any market participant that can at least in part satisfy the order, and matching the entered order at a server system against interest in the market based on how the market participant participates in the market with a portion of the interest in the market being prioritized according to price priority among displayed quotes/orders of market makers, ECNs that do not charge a separate quote-access fee, and non-attributable agency orders of UTP Exchanges, and subsequently by displayed quotes/orders of ECNs that charge a separate quote-access fee, with the quotes/orders of the ECNs that charge a separate quote-access fee being ranked by the amount of the quote-access fee charged.