Oura, a finished wearable company developing smart rings for health monitoring, has secured $75 million in a Series D funding round led by Dexcom, a California-based medical device maker specializing in glucose-monitoring biosensors for diabetes patients. With the new financing, the company’s valuation now stands at $5 billion. Oura plans to use the investment to expand its international footprint in the global market and fuel mergers and acquisitions.