Bitcoin Gold/BTG

Bitcoin Gold was originally released in November 2017, with the next release following in January 2018. As such, it is one of the newest currencies based on the original Bitcoin virtual currency. It is also known as a hard fork of the original. It is a fully open source cryptocurrency with a ledger that began in 2009. There are now over 17 million BTG in existence, and the limit of BTG is given as 21 million. The block reward is halved around every four years, as the currency is mined.