Company · Ownership research

MONOLITHIC POWER SYSTEMS, INC. MPWR

CIK 0001280452

Form 4 transactions dated Nov 1, 2023 to Nov 8, 2026, as reported to the SEC.

Insider trading Initial holdings Institutional holders

This page lists 30 of 41 rows; the complete set is available through the API.

Insider filings on file run through Nov 5, 2026.

Insider purchases & sales

Purchased: $0.00
Sold: $1.17B

Nov 1, 2023 – Nov 5, 2026
Available records · partial months are marked ·

202510 of 30 preview events · 41 available in 2025

Date	Insider	Activity	Trade value (USD)	% of prior holding
Dec 24, 2025	Lee Victor K Director	Sale10b5-1 footnote	$951.72K 1,000 shares sold	3.38% sold Direct holding	▾
Dec 1, 2025	BLEGEN THEODORE EVP and CFO	Sale10b5-1 footnote	$2.72M 3,000 shares sold	4.04% sold Direct holding	▾
Nov 26, 2025	Tseng Saria EVP & General Counsel	Sale	$18.53M 20,000 shares sold	10.68% sold Direct holding	▾
Nov 25, 2025	Tseng Saria EVP & General Counsel	Sale	$18.08M 20,000 shares sold	9.65% sold Direct holding	▾
Nov 25, 2025	CHANG KUO WEI HERBERT Director	Sale	$89.70K 100 shares sold	19.01% sold Direct holding	▾
Nov 24, 2025	Sciammas Maurice EVP, WW Sales & Marketing	Sale	$3.56M 3,976 shares sold	2.68% sold Direct holding	▾
Nov 21, 2025	CHANG KUO WEI HERBERT Director	Sale	$87.40K 100 shares sold	15.97% sold Direct holding	▾
Nov 19, 2025	Sciammas Maurice EVP, WW Sales & Marketing	Sale	$24.66M 27,966 shares sold	15.87% sold Direct holding	▾
Nov 19, 2025	Sciammas Maurice EVP, WW Sales & Marketing	Sale	$6.12M 7,034 shares sold	3.84% sold Direct holding	▾
Nov 12, 2025	Hsing Michael CEO · Director	Sale	$35.72M 37,000 shares sold	3.87% sold Direct holding	▾

Showing 30 / 41 record groups in 2025. The complete set is available through the API.

MONOLITHIC POWER SYSTEMS, INC. · MPWR

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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 30 of 41 purchase / sale groups and 30 of 39 other groups; the totals and the monthly series cover the whole window.

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{"action":"list","ticker":"MPWR","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.