Intelligent information dissemination

A computer-implemented electronic exchange comprising:

• a transmitter configured to transmit from a computer-implemented electronic exchange to electronic clients a data message including a current list of items sorted in order by the computer-implemented electronic exchange prior to transmission, where the list of sorted items represents a current orderbook of the computer-implemented electronic exchange and includes pending sorted buy or sell orders for a particular financial instrument, and where a first electronic client subscribes to the first X sorted items of the current list, X being a positive integer and in a range of 1-20, and a second electronic client subscribes to the first Y number of sorted items of the current list, where Y>X, and
• electronic circuitry configured to detect when an item is removed from, added to, or updated in the first X sorted items of the current list to produce a new list of first X sorted items based on an update data message received at the computer-implemented electronic exchange that indicates a change in relative position from the top of the current list of at least one of the pending sorted buy or sell orders for the particular financial instrument;
• and
• the transmitter, in response to the detection, configured to transmit a broadcast data message to both the first and second electronic clients that includes the item removed from, added to, or updated in the first X sorted items to inform the first and second electronic clients of the removed, added, or updated item without having to receive the entire new list so that the first and second electronic clients can manipulate their corresponding sorted items of the current list using the item removed from, added to, or updated in the X sorted items.

A client computer for managing a client list of items sorted in an order by a computer-implemented electronic exchange prior to transmission to the client computer, where the sorting is in accordance with a value of a market parameter, where the list relates to transactions in the computer-implemented electronic exchange and includes pending sorted buy or sell orders for a particular financial instrument, where the client subscribes to the first X sorted items of a current list of sorted items in the computer-implemented electronic exchange, X being a positive integer and in a range of 1-20, and the current list of sorted items representing a current orderbook of the computer-implemented electronic exchange, the client computer comprising:

• an interface configured to receive a data message from the computer-implemented electronic exchange including the first X sorted items from the current sorted list as the client list;
• a memory configured to store a set of X sorted items;
• a display configured to display the first X sorted items from the current sorted list as the client list;
• the interface being configured to receive a broadcast data message from the computer-implemented electronic trading exchange indicating removal, addition, or updating of one item in the current sorted list, and
• a message handler configured to manage the set of X sorted items and remove, add, or update a corresponding item from the set of X sorted items if the received broadcast data message indicates removal, addition, or updating, respectively, of one of the first X sorted items without having to receive an entire new list of X sorted items.