A study by block chain evidence company Chainalysis found that many BTC holders have lost their keys for a variety of reasons and can not retrieve their BTC. The number of statistical losses should be around 3 million 790 thousand, accounting for 18% of the total BTC supply of 21 million, considering that the price calculation of BTC is through the city of digital assets. Field estimation is divided by the supply of its cycle, so when the supply of bitcoin reaches 21 million, the price of BTC should be 18% higher than the actual price.