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Masimo shareholders approve sale to Danaher

Masimo shareholders approve sale to Danaher

Money Moves

Stockholders back $180-per-share cash deal valuing the patient-monitoring firm at $9.9 billion, ending a four-year arc from activist takeover to strategic exit.

May 4th, 2026: Masimo shareholders approve Danaher merger

Overview

Eighteen months after activist investor Politan Capital ousted Joe Kiani from the board of the medical-device company he founded in 1989, Masimo shareholders voted to sell it to Danaher for $9.9 billion. Roughly 37 million shares favored the deal; 17,061 opposed it, and 14,035 abstained.

The vote completes a textbook activist playbook: take a minority stake, win board seats, replace the founder, refocus the business, deliver a premium exit. Once the deal closes later in 2026, Masimo's pulse oximeters and hospital patient-monitoring systems will fold into Danaher's Diagnostics segment alongside Cepheid, Beckman Coulter, Leica Biosystems, and Radiometer. This consolidates another large piece of the U.S. medical-device market under a single owner.

Why it matters

A 9% activist stake just produced a $9.9 billion sale of a company whose monitors sit in nearly every U.S. hospital—reshaping who controls critical medical technology.

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Key Indicators

$9.9B
Total deal value
Enterprise value including assumed debt, net of acquired cash.
$180
Per-share cash price
Each Masimo share converts to $180 in cash at closing.
99.95%
Shareholder approval
Roughly 37 million shares voted yes; only 17,061 voted against.
9%
Politan's original stake
Activist fund Politan Capital used a single-digit holding to win two board fights.
2
Proxy fights won by Politan
Activist won board seats in 2023 and 2024, ousting founder Joe Kiani.
H2 2026
Expected close
Subject to regulatory clearances and customary conditions.

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People Involved

Organizations Involved

Timeline

April 2022 May 2026

10 events Latest: May 4th, 2026 · 1 month ago
Tap a bar to jump to that date
  1. Masimo shareholders approve Danaher merger

    Latest Vote

    Masimo announces that stockholders overwhelmingly approved the merger agreement, with roughly 37 million shares in favor and only 17,061 against. The deal still requires regulatory clearance.

  2. Danaher announces $9.9 billion acquisition of Masimo

    Corporate Action

    Danaher agrees to buy Masimo for $180 per share in cash, valuing the company at approximately $9.9 billion including assumed debt. Masimo will join Danaher's Diagnostics segment.

  3. Sound United sale to Samsung's Harman closes

    Divestiture

    Masimo completes the $350 million sale of its Sound United consumer-audio business to Harman International, undoing the 2022 acquisition that triggered the activist campaign.

  4. Katie Szyman named CEO

    Leadership

    Former BD and Edwards Lifesciences executive Katie Szyman takes over as Masimo CEO with a mandate to refocus the company on its medical-device core.

  5. Politan wins second proxy fight, ousts founder Kiani

    Governance

    Shareholders vote Joe Kiani off the Masimo board, electing Politan nominees Darlene Solomon and Bill Jellison instead. Kiani resigns as CEO days later.

  6. Politan wins first proxy fight

    Governance

    Shareholders elect Koffey and healthcare veteran Michelle Brennan to the Masimo board over management's preferred slate.

  7. Politan Capital discloses ~9% Masimo stake

    Activist Campaign

    New York activist fund Politan Capital, run by Quentin Koffey, surfaces as a major Masimo shareholder, citing the destruction of value from the Sound United deal.

  8. Masimo announces $1 billion Sound United acquisition

    Corporate Action

    Masimo agrees to buy consumer-audio company Sound United, parent of Denon, Marantz, and Bowers & Wilkins. The pivot away from medical devices stuns investors and the stock falls more than 35% in the following months.

Historical Context

2 moments from history that rhyme with this story — and how they unfolded.

April–August 2017

Whole Foods sold to Amazon after Jana Partners pressure (2017)

Activist fund Jana Partners disclosed an 8.8% stake in Whole Foods in April 2017, criticized management, and pushed for a sale or operational overhaul. Within ten weeks, Amazon agreed to buy the grocer for $13.7 billion at a 27% premium. The deal closed in August 2017.

Then

Whole Foods shareholders received a substantial premium; founder John Mackey stayed on briefly before retiring. Jana Partners exited with sizable gains.

Now

The deal demonstrated how a single-digit activist stake could trigger a billion-dollar sale of a founder-led company to a strategic acquirer, becoming the template playbook later imitated at Masimo and elsewhere.

Why this matters now

Same mechanism: minority activist stake creates board pressure, founder loses control, company sells to a deep-pocketed strategic buyer at a premium. Politan executed the longer-cycle version of the Jana playbook.

February 2014

Forest Laboratories sold to Actavis after Icahn campaign (2014)

Carl Icahn took a roughly 11% stake in Forest Labs in 2011 and ran two proxy fights against the founding Solomon family, eventually winning four board seats. In February 2014, Forest agreed to sell to Actavis for $25 billion, with Icahn's stake worth approximately $1.7 billion at the deal price.

Then

Founder Howard Solomon's son Andrew, who had been groomed as successor, never took over. Forest's specialty-pharma franchise was absorbed into Actavis.

Now

Actavis later became Allergan, then was acquired by AbbVie in 2020 for $63 billion, putting Forest's assets through three owners in six years—a cautionary case for how activist-driven sales can accelerate further consolidation.

Why this matters now

Closest medical-industry parallel: minority activist holding (~10%), multiple proxy fights, founder family ousted, strategic sale at a large premium. The Masimo sequence compresses essentially the same script.

Sources

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