Ryuk is one of the most dangerous Ransomware families. It is (allegedly) run by a specialized cybercrime actor that during the last 2 years mainly focused on targeting enterprise environments. The amount of bitcoins demanded in their ransom attacks varies depending on the target. Some of the wallets used by the group to collect the ransom payments reached millions of dollars in a few weeks.
Protecting against such attacks is one of the main priorities for any CISO or security team. This is a problem that should be approached from different perspectives, being prevention (likely) the most relevant one.