IN PLAIN ENGLISH
What your cards would roughly sell for today, going by TCGplayer's market price for the exact printing you own.
FULL DEFINITION
The market value of the trading cards and sealed product you have added, each at the price of its own printing.
EXAMPLE
Two Normal Pikachu at $6.43 and one Holofoil Charizard EX at $28.53: 2 × 6.43 + 28.53 = $41.39, which at a USD→GBP rate of 0.738 is £30.55.
HOW IT'S CALCULATED
Collectible Card Value = Σ (copies × that printing's market price in USD) × the latest stored daily USD→currency rate. Prices are TCGplayer's market prices as recorded by TickerMint once a night; we reuse a price for up to three hours. A card counts only at the printing you picked (Normal, Holofoil, Reverse Holofoil, 1st Edition…), never at another printing's price. A card is left out and flagged while it is still being priced (a large collection is priced a batch at a time), when its printing has no market price today, or when TickerMint no longer lists it. With no exchange rate for your currency, the whole collection is left out of your totals and prices show in USD only. Condition and grading are not taken into account: it is the market price for an ungraded copy (TickerMint describes it as raw near-mint), so a played or a graded card can be worth noticeably less or more.
Educational content only. It is not personal financial advice.