Company · Ownership research

MASIMO CORP MASI

CIK 0000937556

Form 4 transactions dated Nov 1, 2023 to Nov 11, 2026, as reported to the SEC.

Insider trading Initial holdings Institutional holders

This page lists 30 of 57 rows; the complete set is available through the API.

Insider filings on file run through Jun 12, 2026.

Some filings are submitted jointly by several insiders. The SEC form does not apportion the reported figures between them, so results include every joint filer.

Insider purchases & sales

Purchased: $468.50K
Sold: $15.00M

Nov 1, 2023 – Jun 12, 2026
Available records · partial months are marked ·

20256 of 6 preview events

Date	Insider	Activity	Trade value (USD)	% of prior holding
Aug 13, 2025	Brennan Michelle Director · Chairman of the Board	Purchase	$15.53K 100 shares bought	1.39% added Direct holding	▾
Aug 12, 2025	Brennan Michelle Director · Chairman of the Board	Purchase	$15.04K 100 shares bought	1.40% added Direct holding	▾
Aug 11, 2025	Jellison William R Director	Purchase	$437.94K 3,000 shares bought	167.60% added Direct holding	▾
May 12, 2025	Muhsin Bilal Chief Operating Officer	Sale10b5-1 footnote	$1.63M 10,000 shares sold	29.26% sold Direct holding	▾
Mar 14, 2025	REYNOLDS CRAIG B Director	Sale10b5-1 footnote	$341.07K 2,053 shares sold	11.02% sold Direct holding	▾
Mar 10, 2025	Muhsin Bilal Chief Operating Officer	Sale10b5-1 footnote	$5.02M 30,000 shares sold	55.38% sold Direct holding	▾

Showing 6 / 6 record groups in 2025. The complete set is available through the API.

MASIMO CORP · MASI

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The initial HTML of this page carries its exact data as script#research-data (JSON): values, units, scope, preview limits and SEC sources. Read it directly, no script or API key needed; script#research-access says what needs an account. For the year shown, this page lists 6 of 6 purchase / sale groups and 30 of 57 other groups; the totals and the monthly series cover the whole window.

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{"action":"list","ticker":"MASI","transaction_code":["P","S"],"transaction_form_type":"4","page_size":20}

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Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.

Non-cancelled, non-derivative purchase (P) and sale (S) rows dated inside the public window, as reported. Share totals are on today's split-adjusted basis. Includes open-market and private transactions. Data after the latest filing is not asserted complete and is not zero-filled. A grouped event shares filing, transaction date, security, code, direction, ownership bucket and source. Derivative groups also match underlying security, exercise price, exercise/expiration dates and footnote references. Reported rows are retained; P/S price lots can be grouped. Post-transaction balances are never summed.