4K is the most reliable and cost-effective place to buy Casascius coins. We offer best-in-class authentication and low fees so that you can be confident the coin you buy is authentic and unpeeled.

First, we inspect the casing in which the grading company placed the coin to ensure it is the same as the coin that was graded. We also examine the tamper-evident hologram with a microscope to search for any signs of peeling.

To be confident beyond any reasonable doubt, we also check the public key to confirm that funds have not moved since minting.

4K uses NFTs to streamline the transaction process for physical assets. By holding your Casascius coin in NFT form, you do not have to reauthenticate with each trade, physically settle with each trade, or securely store your assets. You can redeem your NFT for the physical item at any time.

Also, for the lolz ;)

While some of a Casascius coin’s value comes from the Bitcoin that is stored on the coin, the premium paid for Casascius coins comes from the collectible nature of these coins. Each passing day makes it all more impressive that a given coin has not been peeled. You’ll have a hard time defending your identity as a “Bitcoin maxi” if you don’t own at least one Casascius coin.

All you need to do is reach out to us at [email protected]. Our concierge will follow up with clarifying questions as needed and send you a pre-paid, fully-insured shipping label that you can use to send us your coins. If your coins pass our authentication, we will store them in our vaults and issue you physically-backed NFTs that you can list for sale on our marketplace. If they fail authentication, we will send the coins back to you.