TOKYO, JAPAN - JANUARY 25: A worker polishes a brass Bitcoin medal produced by Sakamoto Metal at a workshop on January 25, 2018 in Tokyo, Japan. Sakamoto Metal, a custom medal, coin and pin badge maker in Tokyo, produces 24K gold and brass bitcoin medals that went on sale in January as investments in cryptocurrencies become popular in the country after Japan's government passed a law recognising bitcoin and other alternative coins as legal tender in 2017. (Photo by Tomohiro Ohsumi/Getty Images)
TOKYO, JAPAN - JANUARY 25: Gold Bitcoin Ver 2.0 gold medals produced by Sakamoto Metal are seen at a workshop on January 25, 2018 in Tokyo, Japan. Sakamoto Metal, a custom medal, coin and pin badge maker in Tokyo, produces 24K gold and brass bitcoin medals that went on sale in January as investments in cryptocurrencies become popular in the country after Japan's government passed a law recognising bitcoin and other alternative coins as legal tender in 2017. (Photo by Tomohiro Ohsumi/Getty Images)
TOKYO, JAPAN - JANUARY 25: Brass bitcoin medals produced by Sakamoto Metal are seen at a workshop on January 25, 2018 in Tokyo, Japan. Sakamoto Metal, a custom medal, coin and pin badge maker in Tokyo, produces 24K gold and brass bitcoin medals that went on sale in January as investments in cryptocurrencies become popular in the country after Japan's government passed a law recognising bitcoin and other alternative coins as legal tender in 2017. (Photo by Tomohiro Ohsumi/Getty Images)
TOKYO, JAPAN - JANUARY 25: A worker polishes a brass Bitcoin medal produced by Sakamoto Metal at a workshop on January 25, 2018 in Tokyo, Japan. Sakamoto Metal, a custom medal, coin and pin badge maker in Tokyo, produces 24K gold and brass bitcoin medals that went on sale in January as investments in cryptocurrencies become popular in the country after Japan's government passed a law recognising bitcoin and other alternative coins as legal tender in 2017. (Photo by Tomohiro Ohsumi/Getty Images)
TOKYO, JAPAN - JANUARY 25: Sakamoto Metal President Kunio Sakamoto makes final touches to a metal mold for a bitcoin medal at the company's workshop on January 25, 2018 in Tokyo, Japan. Sakamoto Metal, a custom medal, coin and pin badge maker in Tokyo, produces 24K gold and brass bitcoin medals that went on sale in January as investments in cryptocurrencies become popular in the country after Japan's government passed a law recognising bitcoin and other alternative coins as legal tender in 2017. (Photo by Tomohiro Ohsumi/Getty Images)
