Captive supplies have been a contentious issue in the livestock industry for fifteen years and the subject of both theoretical and empirical research. In 2001, mandatory price reporting was implemented. One objective by its proponents was to increase the amount of information available on captive supplies. This paper examines data now available as a result of mandatory price reporting to determine what additional information is available compared to previously. Second, several models were specified and estimated to determine the impacts captive supplies had on fed cattle prices in the two years following implementation of mandatory price reporting. Models showed mixed results. There was a consistent negative effect on cash market prices from formula priced trades; generally a positive impact from negotiated trades and packer owned trades on cash market prices; and mixed but often a positive impact from forward contract trades on cash market prices.