Last week over 200 packages of graded trading cards being shipped back to their owners were stolen from a Fedex truck parked outside the headquarters of Professional Sports Authenticator (PSA) in Santa Ana, California, according to a report by The Athletic. PSA is one of the largest third-party sports and hobby card grading companies in the world and it reported to the Santa Ana Police Department that the majority of the stolen packages had an approximate value of over $963,000, but that amount could further increase as PSA continues the process of confirming exactly which cards included in the shipment were taken.

In a statement shared to its website, Collectors Holdings, the parent company of PSA, acknowledged the theft and that it’s working closely with local law enforcement and Fedex as the investigation continues. In response to the incident the company says it has “notified marketplace partners so they can be on the lookout for rare and serialized items” to help prevent the stolen cards from being resold. All cards graded by PSA are assigned a unique certification number that the company has since deactivated for all the cards that have so far been identified as stolen.

Collectors Holdings also says it has contacted affected customers to arrange compensation based on the fair market value of their missing collectibles, but “up to the maximum insured value for each item selected by the customer prior to grading,” according to the report.

In a video posted over the weekend, YouTuber Sky-B Cards identified themselves as one of the victims of the theft and shared the response they were sent by PSA. They had paid $8,468 to have 104 collectible sports cards graded by the company, many of which are irreplaceable, and had opted to insure the order for up to $156,000. It is not yet known what compensation they have received. Other collectors affected by the incident have started to reach out to another YouTuber, Boston Card Hunter, who is working to compile a shared list of serialized cards that were stolen including detailed descriptions of each one in hopes it can help other collectors identify them.