Derby futures

The speed of legal sports betting's expansion across America in the last four years has surprised even the most bullish advocates. On any given day in a majority of states, Americans can bet on just about any outcome in the world of sports. The next point in a game of tennis. The total runs in the next inning of a baseball game. The number of corner kicks for a team in a soccer match. But if you legally wanted to bet on the Kentucky Derby other than the day before...