Japanese cryptocurrency exchange Coincheck was hacked and saw the theft of $543mn worth of customer holdings; the Japanese regulator, FSA, said it was concerned that most of the funds were kept in hot wallets online, instead of cold wallets offline; seeing that this is not the first hack of a hot wallet model the regulators might start mandating customer funds be held offline; nothing has been passed yet but the more thefts we see the more regulators will look to try and mitigate future issues. Source.
