PSA has graded more than 1.7 million Michael Jordan basketball cards in its history. Five Jordan cards have been graded more than 30,000 times by the company. Those cards help tell the story of arguably the greatest career in NBA history.

A basketball card featuring Hall of Famers Michael Jordan and Kobe Bryant has become the most valuable basketball card ever.

Sports fans with deep pockets are currently in a bidding war over a one-of-a-kind Michael Jordan and Kobe Bryant basketball card expected to sell for over $6 million. Check out the card -- it's from the 2007-08 Upper Deck Exquisite Collection and features autographs from each basketball legend alongside different NBA logo patches.