Danaher closes in on nearly $10bn deal for medical device maker Masimo
Technology company known for pulse oximeters is in a long-running intellectual property dispute with Apple
US life sciences manufacturer Danaher is closing in on a nearly $10bn deal to buy medical technology company Masimo, two years after an activist investor overhauled the device maker’s board.
A deal for the California-based Masimo could be announced as early as Tuesday provided it does not hit any last-minute snags, according to people familiar with the matter.
The acquisition values Masimo at around $9.9bn, the people said. That represents a premium to its nearly $7bn market capitalisation at Friday’s close.
Danaher, based in Washington, is a sprawling life sciences conglomerate, making laboratory equipment essential to drug discovery and diagnostics for a wide range of diseases. It has been an aggressive M&A dealmaker over the past 25 years.
Masimo is a leading manufacturer of pulse oximeters, which measure blood oxygen levels. The company has challenged Apple over breaching its patents in a long-running intellectual property dispute over the Apple Watch.
Two years ago, hedge fund Politan Capital Management successfully ran a proxy contest that ousted Masimo’s founder, Joe Kiani, as board chair. He quickly resigned as chief executive.
Kiani still owns approximately 5 per cent of the company’s shares, according to S&P Capital IQ. Politan, founded by the Elliott Management alumnus Quentin Koffey, owns nearly 9 per cent of Masimo.
The Masimo deal would be Danaher’s biggest acquisition in more than half a decade since its $21.4bn takeover of Cytiva, the biologics manufacturing arm previously owned by GE Life Sciences.
Masimo shares are down 50 per cent over the past five years and the group has struggled since it acquired Sound United, a wearables company, for $1bn in 2021.
Politan made the purchase of the company with its portfolio of audio brands such as Bowers & Wilkins a key part of its activist campaign, arguing that it strayed from the company’s core area. Politan eventually secured four board seats. In 2025, Masimo sold the wearables group for just $350mn.
Danaher’s stock surged during the Covid-19 pandemic, but has struggled since. It is down 28 per cent from its all-time high in September 2021, giving it a market value of $150bn at Friday’s close.
Its last sizeable acquisition was its $5.7bn takeover of UK life sciences group Abcam in 2024. Danaher has spun out several publicly listed multibillion-dollar affiliates over the years such as Veralto, Envista, and Fortive.
Danaher and Masimo did not immediately respond to requests for comment.