Does it track my profit and loss when I sell cards?
Yes — record what you paid, mark cards sold at their sale price, and your portfolio shows realized profit/loss alongside current holdings.
Yes. Every saved card can carry a cost basis (what you paid), and when you sell one you mark it sold at the sale price — it moves out of your live portfolio into a realized profit/loss ledger. The Portfolio tab shows your holdings' current value, today's change, gain/loss against what you paid, and your all-time realized P&L from sales. You can also organize cards into binders, track cards you've sent to graders (with fees, so the ROI math stays honest), export everything to CSV, and view values in your own currency. It works the same on the mobile app and the web.