Oura Health Oy, a Finnish maker of smart rings that track health, fitness and sleep, is seeking to raise up to $3 billion in a U.S. initial public offering (IPO) that could come as early as September, according to Bloomberg.

Sources told Bloomberg that the IPO will target a company valuation of more than $16 billion. Existing investors are expected to sell a significant amount of stock in the offering, according to the report. In May, reports arrived that Oura filed confidentially for a U.S. IPO.

The $16 billion valuation would mark a sizeable step-up from recent valuation levels. Last September, Oura achieved an $11 billion valuation following an $875 million Series E funding round.

The firm is reportedly working with an underwriting syndicate that includes Goldman Sachs Group Inc., Morgan Stanley, JPMorgan Chase & Co., Allen & Co., and Jefferies Financial Group Inc.

Image courtesy Oura