The contract makes Bryant, picked second overall by Chicago, the most highly paid draftee of the 2013 class thus far. First overall pick Mark Appel was given a $6.35 million bonus by the Houston Astros. Bryant's bonus was also the largest ever given out by the Cubs to a draft pick, topping Mark Prior's $4 million in 2001.
Bryant, 21, was the College Player of the Year in 2013 after hitting 31 home runs with a .329/.493/.820 line over 62 games for the University of San Diego.
General manager Jed Hoyer said that Bryant was likely to start his professional career with Class-A Boise.
Bryant was one of just four players chosen in the first round of the 2013 draft who had not yet signed a deal. The remaining three are Colin Moran (Marlins), Phil Bickford (Blue Jays), and Aaron Judge (Yankees).