Bitcoin's scarcity increases every day, but the most iconic set of physical bitcoins—the Casascius series—has become even rarer than its digital counterpart. As of September 18, 2021, fewer than 20,000 Casascius physical bitcoins remain active, meaning their embedded BTC has not yet been redeemed (peeled).
Casascius Collection Shrinks Rapidly
Created by Mike Caldwell between 2011 and 2013, Casascius physical bitcoins feature a holographic tamper-evident sticker that, when removed, exposes the private key allowing the holder to spend the loaded bitcoin. Caldwell minted three series: Series 1 (1–1,000 BTC), Series 2 (0.5–500 BTC plus DIY Storage Bars), and Series 3 (0.5–1 BTC). The U.S. government eventually forced Caldwell to stop producing new loaded coins. In total, he minted approximately 27,920 Casascius units.
According to data from casasciustracker.com, as of September 18, 2021, there are roughly 19,920 active Casascius coins and bars waiting to be peeled. Over the past decade, 8,009 units have already been redeemed. The remaining unpeeled stash contains about 43,000 BTC, which at the time was worth over $2 billion. In contrast, 48,169 BTC (valued at $2.3 billion) have already been spent through the peel process.
High-Value Denominations Still Intact
Among the rarest items are the Series 1 1,000 BTC coins. Out of six minted, only two have been redeemed, meaning four coins each worth roughly $48 million remain whole. Of the 16 Series 1 1,000 BTC bars, 87.5% (14 bars) have been peeled. For the Series 2 100 BTC coins, Caldwell produced 81 pieces; 58.02% (47 coins) have been redeemed, leaving 34 coins each worth $4.8 million still active.
The Casascius series has gained significant numismatic value. Even peeled (empty) coins trade for premiums. For example, a 2012 peeled Casascius coin sells for $1,999. A 2013 silver Casascius coin still loaded with 0.1 BTC ($4,834 at the time) is listed at $20,000. A rare set of 125 aluminum empty Casascius coins is offered for $4,995.
The fact that fewer than 20,000 Casascius units remain active underscores the collection's transformation from a novelty to a highly sought-after historical artifact. Each subsequent peel reduces supply further, potentially driving up the premium for intact coins. Collectors and crypto enthusiasts alike watch the tracker closely, as the window to own a fully loaded piece of early bitcoin history grows ever narrower.