Systems, methods and computer program products for trading financial instruments are described herein. A first order to buy or sell a financial instrument is received, where the first order includes at least one contingency. The contingency may be price-based and/or volume-based. For example, the contingency can be based on a volume-weighted average price of the security (VWAP); a time-weighed average price of the security (TWAP); a target trading volume of the security as a percentage of total market volume during a specified period (TVOL); or a net asset value (NAV) of the security. The first order is matched with a corresponding second order. For example, a bid for a given security is matched with an offer for the same security. This matching operation also includes ensuring that the contingency(ies) of the first order are compatible with the contingency(ies) of the second order. Thereafter, the contingencies are calculated, and then the first and second orders are executed pursuant to the calculated contingencies.