According to Internet reports, according to Cryptoslate, a collector who called himself John Galt on the Bitcoin Talk forum recently successfully redeemed a solid gold Casascius physical Bitcoin gold bar purchased in 2012 and extracted 100 BTC pieces, currently worth more than 10 million US dollars. It is reported that the purchase price of the gold bar was only US$500 that year, and the return on investment was as high as approximately 2,000,000%. Casascius physical bitcoin was issued by Mike Caldwell in 2011 and embedded with the real bitcoin private key. It was discontinued in 2013 due to regulatory pressure and has now become a rare collectibles in the history of encryption. According to data from casasciutracker.com, more than 10,000 Casascius coins have been redeemed, and more than 18,000 are still unused.