Oura, the maker of smart rings that track your heartbeat and sleep, has pulled its plan to sell shares on the US stock market just days after announcing it - a flotation that would have valued the company at $15bn (£11.3bn).

The firm said it would postpone its listing "due to uncertainty in the Initial Public Offering (IPO) market" and declined to say when it might try again. Which is corporate for: we'll be back when the vibes improve.

Oura had filed official documents setting out plans to raise up to $2.2bn by offering shares to investors just over a week earlier. It had planned to sell shares priced between $40 and $44 on the Nasdaq, giving it that $15bn implied market value. So close. And yet so far.

The company becomes the latest in a growing queue of businesses delaying their public listings, with experts noting the IPO market is getting more challenging - a phrase that has never once preceded good news.

Oura's chief executive Tom Hale said "an IPO is just one step in our journey," adding that "we have the luxury of choosing our moment." A luxury, sure, in the same way that not getting on a rollercoaster is a luxury.

Earlier this month, US nuclear technology firm Holtec International also postponed its flotation, blaming an "unusual confluence of developments that has impaired investor confidence in the market for new public offerings." Specifically: rising energy costs, military conflicts, global trade tensions, and inflation concerns that have led central banks including the US Federal Reserve to raise benchmark interest rates. This week, the yield on US debt repayable in 10 years' time hit its highest level since 2007. Nothing says "buy our stock" like a 16-year high in borrowing costs.

Samuel Kerr, global head of equity capital markets at Mergermarket, said: "What is now clear is we are in a very different IPO market to the one we envisaged just a few weeks ago."

Financially, Oura is not exactly floundering. In its last full financial year ending 30 September 2025, it made a pre-tax profit of $23.5m on sales of $907.8m - up from a $6.2m pre-tax profit the previous year. Its most recent figures for the nine months to 30 June this year show pre-tax income of $70m on sales of $1.2bn. So the rings are selling. The question of whether they do what they claim is another matter.

Oura, founded in Finland in 2013 and now headquartered in San Francisco, makes smart rings costing upwards of $300 that monitor things like heartbeat and sleep patterns, which are analysed and presented on an app. The company is also the subject of a class action lawsuit accusing it of false advertising by claiming its rings can accurately track a person's sleep activity and patterns.

The lawsuit, filed by the Clarkson Law Firm in August, claimed: "Oura rings cannot measure one's sleep or cycles. That's because sleep happens in the brain, not on one's finger." It is understood that Oura's decision to delay the IPO is not connected to the lawsuit - because nothing says "unconnected" like a $15bn delay announced days after the paperwork went in.

In a statement, an Oura spokesperson said: "We stand behind our science, research and accuracy claims." They added: "Like other consumer sleep wearables, Oura Ring estimates sleep stages using multiple physiological signals, including heart rate, heart rate variability, movement, breathing patterns, and temperature."

So the ring knows your heart rate, your breathing, your temperature, and your movement. Whether it knows you're asleep is, apparently, a matter for the courts.