Hi YC, I’m Joseph Zhang and I’m working with my cofounder Sophia Kim to build CatchBack Cards,  an iOS and web platform for maximizing the thrill of collecting Pokemon and Sports cards. We allow collectors to create custom mystery packs with personalized chases and customized odds with cryptographically trusted tooling. Users can rip open digital packs and get physical cards shipped to them, receive buyback offers on cards pulled from their mystery packs sent straight to Venmo and PayPal, and buy/sell cards in our $1 marketplace.

https://www.youtube.com/watch?v=nFLVCQQhvcE

What we’re building

The trading card market is massive, fast-growing, and very large in transaction volume. Globally, physical trading cards (sports, Pokémon, anime like One Piece, etc.) represent a $20B+ annual market, growing at double-digit rates (~10–15% YoY) even after the pandemic boom. Beyond retail sales, billions of dollars move through the secondary market each year via graded cards, private deals, and resale platforms. What’s striking is how offline this economy still is: at local and regional card shows, millions of dollars change hands over a single weekend, through cash deals, trades, box breaks, and private six-figure transactions—most of it fragmented, informal, and poorly tracked. This is a real, high-velocity market hiding in plain sight.

Mystery packs are popular in Pokémon and sports cards, but today they’re mostly run manually or through platforms with high fees and limited transparency. CatchBack lets anyone create their own mystery packs with their desired pool of cards, risk levels, and personalized odds, and gives collectors the option to buy packs, to list cards in the marketplace, and to get an instant buyout offer on whatever they hit in the pack. We provide cryptographic randomness proofs and open source our card selection code so that users can independently verify and trust our mystery packs. Users trust our packs more because they can pick exactly what goes into their pool and can see mathematical proof, which physical mystery packs cannot recreate.

We’re also building a platform that digitizes cards and allows users to transact ownership rights to cards for just $1. Previously, eBay buyers dealt with fraud issues, ridiculous hidden fees, and shipping headaches, and we’re creating a system that allows for maximal liquidity and convenience in speculating on card investments.

Who it’s for

Our users are card collectors who open mystery bags and creators (Pokémon, sports cards, slabs) who already sell to communities on Instagram, Discord, and live marketplaces.

Why we started this

We spent a lot of time buying, selling, and comping cards across eBay, Whatnot, and Instagram DMs, and kept seeing the same problems: high fees, fragmented liquidity, and a lack of trust in mystery packs. Other blind box sites stuff their bags with undesirable floor hits and gouge their users on shipping fees, listing fees, and marketplace fees. We’ve built a platform that maximizes dollar value for collectors–maximal cashback with CatchBack.

Current state

We launched our iOS app on Jan 25, 2026. We’re at 700 users and $13K MRR and are growing aggressively week over week. We’re launching a joint collaboration with Steph Curry’s trading card company and looking to connect with other mentors and companies in the trading card space!

How to Participate

We’re offering a free $25 credit on a $25 deposit. Users can create a mystery pack of 5 cards that have a market value of $50, and can be guaranteed one of these $50 cards for a $25 deposit! We offer free shipping on cards. DM us on our instagram @catchback_cards after creating an account on our platform, and we’ll set you up with the credit!