Skip to content
Whale Atlas — Follow the signal.
Home
FULL RECORDS
Search insider filingsAll Congress filings
MORE TOOLS
WatchlistGold IntelligencePeopleCharts & technicalsCompany financialsOfficial newsMy saved workspace
YOUR RESEARCH
HomeSearch insider filingsAll Congress filings
More research tools
ExploreGold IntelligencePeopleInvestigate an ideaCharts & technicalsMore evidenceCompany financialsOfficial newsMy research & helpWatchlistMy saved workspaceLearn the basicsHow signals workData & coverage
RESOURCES
LearnMethodologyData sources
Built on public evidence.

Primary sources. Clear reasoning.
No black boxes.

Our approach
Public research workspacev1.0

Loading data…Scanning SEC filings…Checking Congress reports…Following the signal…

HomeSearchCongressWatchlist
© 2026 Whale AtlasFree public-filing research. Not financial advice. By using this site you agree to the Terms of Use.
FAQCompare trackersMethodologyData & correctionsTermsPrivacy
Back to Home
M

MPWR

Nasdaq

MONOLITHIC POWER SYSTEMS, INC.

Latest disclosureSeptember 30, 2026
Insider score Why 0?
0/ 100
Qualifying buys · 30d
$0

0 purchases · 111 sales

Price by TradingViewDelayed quote from TradingView, for viewing only. It does not power Whale Atlas scores or alerts. If the quote does not load, open the TradingView link.

Insider transactions 122

Limited filing history
All122Buying0Selling111Other11
Filters

Last 30 daysNo qualifying insider buying. Sales: $40.35M by 1 insider.

11 of 122 trades · March 30, 2026 – September 28, 2026Incomplete history: this shows the filings imported so far, not every filing ever made. Dates are trade dates. Filters affect this table only.

Showing the first 6 of 11 trades on this page.

Gift disclosed

Saria Tseng

EVP & General Counsel

Common Stock

Value context
Not a purchase
Reported price
Gift · no purchase price
Understand this price

The filing reports a zero transaction price for this gift. It does not establish the market value of the gift.

Traded August 31, 2026Filed September 2, 2026SEC filing
Gift disclosed

Saria Tseng

EVP & General Counsel

Common Stock

Value context
Not a purchase
Reported price
Gift · no purchase price
Understand this price

The filing reports a zero transaction price for this gift. It does not establish the market value of the gift.

Traded August 31, 2026Filed September 2, 2026SEC filing
Other activity disclosed

Robert W. Dean II

Interim CFO

Common Stock

Value context
Not established
Reported price
$0 reported · see filing
Understand this price

The filing reports a zero transaction price. That is not a current market valuation; inspect the original filing for context.

Traded August 24, 2026Filed August 26, 2026SEC filing
Gift disclosed

Maurice Sciammas

EVP, WW Sales & Marketing

Common Stock

Value context
Not a purchase
Reported price
Gift · no purchase price
Understand this price

The filing reports a zero transaction price for this gift. It does not establish the market value of the gift.

Traded August 4, 2026Filed August 6, 2026SEC filing
Gift disclosed

Maurice Sciammas

EVP, WW Sales & Marketing

Common Stock

Value context
Not a purchase
Reported price
Gift · no purchase price
Understand this price

The filing reports a zero transaction price for this gift. It does not establish the market value of the gift.

Traded August 4, 2026Filed August 6, 2026SEC filing
Award disclosed

Robert W. Dean II

Interim CFO

Common Stock

Value context
Non-cash award
Reported price
Award · no purchase price
Understand this price

The filing reports a zero transaction price for this award. It does not mean the awarded securities have no market value.

Traded July 25, 2026Filed July 28, 2026SEC filing
Gift disclosed

Maurice Sciammas

EVP, WW Sales & Marketing

Common Stock

Value context
Not a purchase
Reported price
Gift · no purchase price
Understand this price

The filing reports a zero transaction price for this gift. It does not establish the market value of the gift.

Traded May 29, 2026Filed June 2, 2026SEC filing
Gift disclosed

Saria Tseng

EVP & General Counsel

Common Stock

Value context
Not a purchase
Reported price
Gift · no purchase price
Understand this price

The filing reports a zero transaction price for this gift. It does not establish the market value of the gift.

Traded May 22, 2026Filed May 27, 2026SEC filing
Gift disclosed

Maurice Sciammas

EVP, WW Sales & Marketing

Common Stock

Value context
Not a purchase
Reported price
Gift · no purchase price
Understand this price

The filing reports a zero transaction price for this gift. It does not establish the market value of the gift.

Traded May 13, 2026Filed May 15, 2026SEC filing
Gift disclosed

Maurice Sciammas

EVP, WW Sales & Marketing

Common Stock

Value context
Not a purchase
Reported price
Gift · no purchase price
Understand this price

The filing reports a zero transaction price for this gift. It does not establish the market value of the gift.

Traded May 13, 2026Filed May 15, 2026SEC filing
Other activity disclosed

Robert W. Dean II

Interim CFO

Common Stock

Value context
Not established
Reported price
$0 reported · see filing
Understand this price

The filing reports a zero transaction price. That is not a current market valuation; inspect the original filing for context.

Traded May 13, 2026Filed May 15, 2026SEC filing
Reporting insiderSecurity / transactionAmount / priceValueTraded / disclosedSource
EVP & General CounselCommon StockGift2,000Gift · no purchase priceNot a purchaseAug 31Filed Sep 2 · 2d laterSEC filing
EVP & General CounselCommon StockGift2,000Gift · no purchase priceNot a purchaseAug 31Filed Sep 2 · 2d laterSEC filing
Interim CFOCommon StockOther transaction5$0 reported · see filingNot establishedAug 24Filed Aug 26 · 2d laterSEC filing
EVP, WW Sales & MarketingCommon StockGift25,000Gift · no purchase priceNot a purchaseAug 4Filed Aug 6 · 2d laterSEC filing
EVP, WW Sales & MarketingCommon StockGift25,000Gift · no purchase priceNot a purchaseAug 4Filed Aug 6 · 2d laterSEC filing
Interim CFOCommon StockGrant or award1,359Award · no purchase priceNon-cash awardJul 25Filed Jul 28 · 3d laterSEC filing
EVP, WW Sales & MarketingCommon StockGift12,472Gift · no purchase priceNot a purchaseMay 29Filed Jun 2 · 4d laterSEC filing
EVP & General CounselCommon StockGift200Gift · no purchase priceNot a purchaseMay 22Filed May 27 · 5d laterSEC filing
EVP, WW Sales & MarketingCommon StockGift1,563Gift · no purchase priceNot a purchaseMay 13Filed May 15 · 2d laterSEC filing
EVP, WW Sales & MarketingCommon StockGift1,563Gift · no purchase priceNot a purchaseMay 13Filed May 15 · 2d laterSEC filing
Interim CFOCommon StockOther transaction2,156$0 reported · see filingNot establishedMay 13Filed May 15 · 2d laterSEC filing

Congress transactions 7

All Congress filings
Full sale disclosedAmended report

Monolithic Power Systems, Inc. - Common Stock · Stock

The filing reports a full sale for a joint account.

Thomas H Tuberville official portraitThomas H TubervilleReporting Senate member
Reported amount
$1,001 – $15,000Reported range; exact amount not disclosed.
Trade date
May 3, 2024
Filed August 5, 2026 · 824d laterOriginal report
Partial sale disclosed

Monolithic Power Systems, Inc. - Common Stock (MPWR) · Stock

The filing reports a partial sale for a spouse.

Byron Donalds official portraitByron DonaldsReporting House member
Reported amount
$1,001 – $15,000Reported range; exact amount not disclosed.
Trade date
June 5, 2026
Filed July 15, 2026 · 40d laterOriginal report
Partial sale disclosed

Monolithic Power Systems, Inc. - Common Stock (MPWR) · Stock

The filing reports a partial sale for the member.

Byron Donalds official portraitByron DonaldsReporting House member
Reported amount
$1,001 – $15,000Reported range; exact amount not disclosed.
Trade date
June 5, 2026
Filed July 15, 2026 · 40d laterOriginal report
Purchase disclosed

Monolithic Power Systems, Inc. - Common Stock · Stock

The filing reports a purchase for a joint account.

Markwayne Mullin official portraitMarkwayne MullinReporting Senate member
Reported amount
$15,001 – $50,000Reported range; exact amount not disclosed.
Trade date
February 4, 2026
Filed March 2, 2026 · 26d laterOriginal report
Purchase disclosed

Monolithic Power Systems, Inc. - Common Stock · Stock

The filing reports a purchase for a spouse.

Markwayne Mullin official portraitMarkwayne MullinReporting Senate member
Reported amount
$15,001 – $50,000Reported range; exact amount not disclosed.
Trade date
January 5, 2026
Filed February 4, 2026 · 30d laterOriginal report
Purchase disclosed

Monolithic Power Systems, Inc. - Common Stock · Stock

The filing reports a purchase for the member.

Markwayne Mullin official portraitMarkwayne MullinReporting Senate member
Reported amount
$15,001 – $50,000Reported range; exact amount not disclosed.
Trade date
January 5, 2026
Filed February 4, 2026 · 30d laterOriginal report
Purchase disclosed

Monolithic Power Systems, Inc. - Common Stock (MPWR) · Stock

The filing reports a purchase for a dependent.

Michael Patrick Guest official portraitMichael Patrick GuestReporting House member
Reported amount
$1,001 – $15,000Reported range; exact amount not disclosed.
Trade date
October 20, 2025
Filed November 19, 2025 · 30d laterOriginal report
Explore furtherTechnical lab Company financials Test a strategy Compare company

Why this buying score?

No qualifying common-equity purchases

No eligible common-equity purchase is public by this cutoff within 180 transaction-date days. Other instruments, exercises and routine activity do not contribute purchase points.

+0 pts

This score describes qualifying insider purchases at issuer level. Read the methodology

Sources and coverage

Limited filing history · Market-wide discovery does not establish complete company history. View coverage
Source
SEC EDGAR · Form 4
Issuer CIK
0001280452
Latest public acceptance
Sep 30, 2026, 09:21 PM UTC
Score calculated
Oct 7, 2026, 12:07 AM UTC
Parser
form4-parser-1.5
Classifier
form4-classifier-1.1
Scoring methodology
insider-experimental-1.1
Availability
Public filing time, not trade date

Open a transaction's SEC filing for the primary evidence. A code P may describe an open-market or private purchase; classification is not proof of intent.

Insider activity can have many explanations. Signal Strength is not a probability of profit or a recommendation to trade.