Many comments have been made over the years on this site about the USDA-report impact on grain markets. Their information gathering and reporting process is respected, generally trusted, and necessary to maintain an unbiased reporting element for the factual component of the information they provide. That said, in this time of vast availability of information, multiple sources public and private, and the speed of information transfer, it is still incredible that an actual report has any relevent element of surprise sufficient to move the markets on any given day. The element of surprise should indicate some type of breakdown, bias or discontinuity in the flow of constant information, from either public or private sources. The movement over the years of the USDA reports, from a primary timely source, to more of a source of confirmation of already known information, is a good thing. Yet, that still does not explain the surprise element, other than the psychology of trading known information, then trading it again when USDA reports it. Otherwise, the market is saying "oops", USDA is right, and we were all wrong, or the opposite. The reports themselves reflect neither supply nor demand changes during the day of the report. It should have no immediate impact on local current cash prices. It is the projected or forecast element of the reports, the crystal ball factor, be it in acres not yet planted, yield not yet known, anticipated demand or usage, projected ending stocks, etc., that impacts perceptions of future elements that impacts futures market prices today. Thus, it is this projection or forecast element of the reports that seems to cause the surprise factor, has become less relevant over time, and again, this is a positive development.
