Hi! Sorry I'm so late responding to this comment.

Basically, some sports cards or trading cards--Like Pokemon cards--can be resold for a lot of money on the aftermarket. Everyday people like you and I are buying them and reselling them for nice profits.

Here's a story about people who were fighting over cards at a Target because of how valuable they are - https://www.nbcnews.com/news/us-news/target-halts-sale-trading-cards-including-pok-mon-over-safety-n1267442