Less than a decade ago, NFL commissioner Roger Goodell condemned sports betting as a scourge that threatened the game’s integrity. If you know of a rollup like this, contact us at rollups(at). This story is part of a new Prospect series called Rollups, looking at obscure markets that have been rolled up by under-the-radar monopolies. These corporations combine the technology of high-frequency trading, the immersive consumer experience of day-trading apps like Robinhood, and the addiction business model of social media.