Banks can be considered as one of the market whales. We are witnessing an increase in banks' reserves from December 2019. Reserve of banks increased about 10 times from November 2020 to February 2021. After that, the price of bitcoin started to rise and in March 2021 it reached ATH, Then, with the decline of the reserve of the banks (sales by banks), the price of bitcoin began to fall. Banks' reserves continue to decline and it reached its lowest level since 2020 now. The increase in banks' reserves in the future can be considered a signal about the possibility of an increase in the price of bitcoin