According to Wu Blockchain, data from Galaxy Research shows that Casascius are physical coins containing Bitcoin private keys. If the hologram is peeled off, the private key is revealed, allowing the BTC to be spent on-chain. Between 2011 and 2013, approximately 28,000 Casascius physical coins were minted, holding a total of 91,469 BTC. Over time, more and more physical coins have been redeemed by their holders. Currently, only about 35,300 BTC remain unredeemed in these physical coins. https://(wublock123.com)/news/casascius-physical-bitcoins-35300-btc-unredeemed-63729