K risto Käärmann is an Estonian entrepreneur who co-founded Wise (formerly TransferWise), a global financial technology company that has revolutionized the field of international money transfers. Before starting his own company, Käärmann worked as a management consultant for Deloitte and PricewaterhouseCoopers, where he advised banks and insurers. His personal experience with the high fees and poor exchange rates charged by traditional banks when sending money abroad inspired him to create a better solution.

Together with his co-founder Taavet Hinrikus, Käärmann launched Wise in 2011 with a simple, transparent peer-to-peer model that significantly lowered the cost of international transfers. As CEO, he has overseen the company's rapid growth from a London-based startup into a publicly-traded global enterprise serving millions of customers. The company has since expanded its services to include a multi-currency account and other cross-border banking features, challenging the dominance of established financial institutions. He is a key figure in the European fintech scene and Estonia's first billionaire.