The Great Material Continuum, sometimes also called the "Great River" or just the "Great Continuum", was a spiritual concept from Ferengi culture.
Ferengi saw the universe as having "millions of worlds, all with too much of one, and not enough of the other", with the Great Continuum flowing through them all like a mighty river, from have to want and back again. As such, it was the force that bound the universe together. To get everything you desire in life, you had to have your ship navigate the Continuum with entrepreneurial skill and grace. In practice, this meant that material taken from one area had to be replaced or paid for through another means, while avoiding obstacles and pitfalls. If one region had a shortage of one type of good, but a surfeit of another, while another region had too much of the former good and a shortage of the latter, then the Great Material Continuum would carry the excess of the one region to ease the dearth in the other. Rom noted that the river could be very treacherous.
The Continuum formed the moral center for Ferengi society. By successfully navigating the Continuum, a great businessman could ensure that people everywhere benefited from his own self-interest by each receiving what he or she wanted. The Nagus in particular was responsible for standing "at the bow of the Ferengi ship of state", navigating the waters of the Great Material Continuum, avoiding the shoals of bankruptcy and seeking the strong winds of prosperity.