Christopher Wood, head of financial strategies at Jefferies, states that he is withdrawing 10% of all bitcoins from his portfolio. The reason for his actions is that quantum computers have recently been developing quite rapidly, and their characteristics threaten the very existence of the entire cryptocurrency due to the fairly high likelihood of breaking the cryptographic protection of these virtual currencies.
Wood first added bitcoins to his portfolio in 2020, and then increased their share to 10% of the entire portfolio in 2021. Now he is getting rid of this 10%.
Bitcoin uses the SHA-256 algorithm, which is (technically) impossible to hack with existing computers, however, quantum computers are predicted to succeed in this task by the 2030s.