F2Pool co-founder Chun Wang reported the loss of 490 bitcoins, worth tens of millions of dollars, to what he described as a “generous hacker,” suggesting the incident stemmed from a private key or operational security failure rather than a direct platform exploit. Wang said the attacker later returned a small portion of the funds, adding an unusual twist to the case. The incident underscores persistent security risks for even highly experienced crypto figures and highlights the importance of robust key management, wallet segregation, and operational safeguards.