There just might be two winners when smart ring maker Oura goes public. Oura, of course, and glucose monitoring company DexCom, which invested $75 million two years ago.

We'll know in a matter of days, when Oura lists on the Nasdaq exchange. But DexCom is set up to rake in big bucks if Oura's IPO goes off smoothly.

DexCom invested in Oura during a private round of financing in November 2024 at a more than $5 billion valuation. Oura's valuation could more than triple from that level with its IPO, which is planned for sometime later in the week at a proposed price of $40 to $44 a share. At the high end of that range, Oura would be worth $15.6 billion.

DexCom, a recent Barron's Investor Circle stock pick, announced the Oura investment as part of a strategic partnership that would integrate DexCom's glucose data with sleep, heart health, stress levels and other biometric data tracked by Oura's rings.

"This powerful combination will attract new shared customers who want to better understand the link between activity, sleep, nutrition and their glucose," said Matt Dolan, executive vice president of strategy and corporate development for DexCom at the time of the announcement.

DexCom wasn't immediately available for comment about the company's investment in Oura and the state of its current partnership. But the possibility of a big gain (on paper at least) for its Oura stake is the latest good news for the company.

The stock is up nearly 20% since Barron's picked it in June and shares are up more than 30% so far this year. Twenty-six of the thirty-one analysts on Wall Street covering DexCom recommend it as a Buy, with the remaining five rating it a Hold.

Earnings are expected to increase nearly 28% this year and by an average of 23% annually over the next few years. The stock still looks reasonably valued too given its growth rate, trading at 29 earnings estimates for the next 12 months.

DexCom isn't the only healthcare company poised to gain from Oura's stock sale either.

Eli Lilly, the pharmaceutical giant that owns the Mounjaro and Zepbound brands of GLP-1 drugs, has a $50 million investment in Oura and has indicated an interest in buying another $100 million of shares in the IPO. Sleep apnea machine maker ResMed also has a partnership with Oura. The company doesn't have an equity stake in Oura though.

But Dexcom and Lilly could financially benefit if Oura's IPO gets a "ring"-ing endorsement from investors.