Operator of the OKX cryptocurrency exchange pleads guilty to violating U.S. anti-money laundering regulations.OKX fined $505 million and agrees to forfeit fees for operating an unlicensed money-transmitting business.Platform allowed U.S.-based users to access in violation of policies, facilitating suspicious transactions worth $5 billion.OKX ranked as the fourth-largest cryptocurrency spot exchange globally and faces growing scrutiny from U.S. regulators.