Multicomputer distributed processing of trading information

A method of interaction between electronic marketplaces to facilitate trade execution, comprising:

• receiving, by a first electronic marketplace, a first indication of a firm order from a broker, in which the firm order defines a side of a trade for a financial instrument;
• transmitting a second indication of the firm order from the first electronic marketplace to a second electronic marketplace without attempting to execute the firm order at the first electronic marketplace;
• receiving, by the second electronic marketplace, the second indication;
• in response to receiving the second indication by the second electronic marketplace, transmitting, by the second electronic marketplace, a third indication of a non-firm order defined by the firm order to the first electronic marketplace;
• receiving, by the first electronic marketplace, the third indication;
• in response to receiving the third indication by the first electronic marketplace, determining a matching order for the non-firm order at the first electronic marketplace, in which the matching order defines an opposite side of the trade for the financial instrument;
• in response to determining the matching order at the first electronic marketplace, confirming by the first electronic marketplace the non-firm order with the second electronic marketplace, and facilitating execution of the trade;
• transmitting a fourth indication that the non-firm order has been fulfilled to the second electronic marketplace from the first electronic marketplace;
• receiving, by the second electronic marketplace, the fourth indication;
• in response to receiving the fourth indication, transmitting from the second electronic marketplace to the first electronic marketplace, a fifth indication that the firm order has been fulfilled;
• receiving, by the first electronic marketplace, the fifth indication;
• and
• in response to receiving the fifth indication, transmitting, from the first electronic marketplace, a sixth indication to the broker that the firm order has been fulfilled.