Over 16,800,000 BTC have been mined as of January 13. It is impossible to predict when all the 21 million will have been mined. Some are saying that it can be done in five years, others argue that will not happen in the next 100 years, as mining will become more difficult.

Originally, 50 bitcoins were earned as a reward for mining a block. It then dropped to 25 bitcoins, and then to 12.5 bitcoins. In 2020, it will fall to 6.25 bitcoins, making mining unprofitable.

Once all 21 million bitcoins have been mined, supply cannot grow — regardless of growing demand. Some people will lose access to their electronic wallets, making supply even smaller. By contrast, cryptocurrency ripple allows miners to create a maximum of 100 billion tokens.

Blockchain-analysis company Chainalysis has estimated that 2.78 million to 3.79 million bitcoins worth up to $50 billion at current prices have already been lost forever. Bitcoin enthusiasts have said this will result in a rapid surge in prices, to levels of up to $100,000 per token.