Despite signing thousands of autographs across more than a decade of movies, Daniel Radcliffe, Emma Watson and Rupert Grint only signed on the same item a handful of times.
One of those, a card from Artbox, following the release of "Harry Potter and the Prisoner of Azkaban", just sold for over $40,000 at Goldin.
Darren Rovell and Will Stern explain what makes this card so special, and why the price of the sale is a good sign for the industry.