Michael Kim’s “Hollywood Economics” has a large section on Avi Arad’s jump from Marvel to his own production company. Here’s a taste:

Just when he helped produced the biggest X-Men movie to date, Avi Arad is leaving as head of Marvel Studio to set up his own production company to be called Avi Arad Prods. Some of the first movies Avi will produce are two future Marvel movies including a sequel to Hulk and Ant Man. As a condition Marvel set for allowing Mr. Arad to leave is he is not allowed to produce a movie based on non-Marvel comic book characters and movies from the sci-fi and fantasy genre. … One possible reason Mr. Arad left, including selling over 3 mm shares of stock in Marvel, is he disagreed with Marvel’s decision to borrow over $500 mm to finance production of its own movies. …

One reason Marvel is taking the risk of financing future movies is it’s not getting much of a slice from the enormous pie generated by movies like the recent smash hit X-Men: The Last Stand.