Your collection's value is based entirely on the numbers you enter — we don't pull eBay sales or auto-update prices for you.

Why? Many graded games have no recent sale to price them from — what's a POP 1 PSA 10 Celeste actually worth? There's often no market answer, so your fair estimate is the best data there is.

Every Sunday night, we snapshot your collection's current total value and plot it as a new point on your chart. Whatever your items are set to at that moment is what gets recorded — permanently.

• Play around freely. Change your values as much as you want during the week — just be sure they're finalized by Sunday 11pm EST, since that's the value the snapshot records.
• Enter fair, accurate values. Whatever a game is set to when the Sunday snapshot lands is what that week's point records — and editing the value later won't retroactively fix a past spike.
• A little upkeep goes a long way. Even updating your values about once a month keeps your history realistic over time.

The chart is only as accurate as the data you give it.