In 1999, a collectible Pokémon card was awarded to a 3rd place winner in a Japanese competition called Super Secret Battle. Based on its historical value, the card's worth snowballed over the years to a whopping $60,000 in 2018. At that time, it sold on eBay and was mailed overseas to the buyer. However, the card, known as Trainer No. 3, vanished in transit, leaving the Pokémon card world in dismay.

Once the seller, pokemonplace, sold the card, it was sent out via USPS mail and was insured for $50,000, which is the most that anyone can insure a package with the service. Unfortunately, tracking ceased shortly thereafter and it never successfully made its way to its final destination.

https://www.polygon.com/2019/7/9/206...er-no-3-bounty

https://www.ibtimes.com/gotta-find-e...t-mail-2806080