Oura, a Finnish smart ring startup, has successfully raised $200 million in funding, resulting in a valuation of $5.2 billion. This funding round has contributed to a doubling of Oura's valuation since its last round. Since its inception in 2015, Oura has sold a total of 2.5 million rings and has raised a cumulative total of $550 million. Notably, sales for the company have surged this year, exceeding $500 million, indicating strong market demand for its AI-powered wearable technology.