Corner the Market

Your entire card collection—values, live eBay comps, grading math, trade analysis—organized and in your pocket.

Corner the Market is the all-in-one portfolio tracker for serious trading card collectors. Whether you collect baseball, basketball, Pokémon, or Magic — track what you own, monitor real eBay prices, and make smarter buy, sell, grade, and trade decisions.

MY COLLECTION Add cards with full details: player, year, brand, card number, parallel, condition, purchase price, and date. Mark cards sold when you flip them. Active and sold cards stay separate, searchable, and sortable.

REAL-TIME EBAY PRICES Look up any card's current market value using live eBay data. See the full price spread with a chart showing Q1, median, Q3, and individual sale prices — not just the cheapest listing.

WATCHLIST Track cards you want to buy. Set a target price and see when market prices drop into your range. Monitor live eBay listings without leaving the app.

TOOLS THAT DO THE MATH · Sale Calculator — real profit after eBay fees, shipping, and cost basis · Should I Grade This? — compare raw vs. PSA 9 vs. PSA 10 eBay prices before you submit · Trade Analyzer — see the real market value on both sides of any trade · Backup & Restore — export and restore your full collection anytime

PORTFOLIO ANALYTICS Value, total invested, win rate, unrealized and realized gains, ROI by year, brand, and condition, top performers, and a portfolio timeline chart.

SUPPORTS ALL MAJOR CARD TYPES Baseball · Football · Basketball · Hockey · Soccer · Pokémon · Magic: The Gathering · Yu-Gi-Oh! · and more