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Monolithic Power Systems (MPWR) Institutional Ownership & Insider Trading History

Top MPWR institutional shareholders, filing changes, and Form 4 insider activity with filters for buys, sales, option exercises, gifts, and tax withholding.

Section freshness

Prices as of Sep 28, 4:00 PM EDT · Fundamentals checked Sep 29, 8:36 AM EDT · Statements Jun 30, 2026

Ownership read

MPWR insider transaction activity: Net selling.

Blackrock Inc. is the largest institutional holder. 82 sales and 0 purchases appear in the recent Form 4 filings. Use the filters below to separate open-market activity from option exercises, gifts, awards, and tax withholding.

Review insider tradesView institutions

Insider flow

MPWR

Purchases0
Sales708.80K

Directional bars ignore awards, gifts, conversions, and tax withholding rows.

Top holder

5.59M

Blackrock Inc.

Insider transaction activity

Net selling

$760.5M sold / $0.0000 bought

Observations shown

130

10 holder / 120 insider

Holder rows
10
Yahoo Finance · Filing dates shown per row
Increased / initiated
4
6 decreased · provider-reported changes
Insider rows
120
Yahoo Finance · Filing dates shown per row

Ownership concentration and transaction activity

Top 10 reported holders
50.44% outstanding
Changes with share-count history
Prior-position data unavailable
New / exited positions
0 / 0 explicitly reported
Largest increase with share-count history
Prior share counts unavailable

Reported-holder cohort only; absence from a limited provider list does not establish an exit. Changes are provider-reported and are only comparable quarter over quarter when the position periods match.

Net shares sold: 708,799

Sale-code S shares minus purchase-code P shares in this sample. Includes disclosed plans and unknown plan status; excludes grants, gifts, exercises and withholding. This is activity, not sentiment.

  • Gift: 15
  • Purchase / sale; plan unknown: 82
  • Grant: 23

Top 10 institutional holders

Monolithic Power Systems (MPWR) institutional ownership

Ranked by reported share count, with position changes and separate position and filing dates where ownership data supplies them.

Monolithic Power Systems (MPWR) institutional ownership
#Institution% heldSharesChange %Position / filing date
1
Blackrock Inc.
11.4%5.59M-7.95%Position as of Jun 30, 2026Filing date unknown
2
FMR, LLC
10.5%5.18M+17.64%Position as of Jun 30, 2026Filing date unknown
3
Vanguard Capital Management LLC
6.36%3.13M+1.40%Position as of Jun 30, 2026Filing date unknown
4
Vanguard Portfolio Management LLC
5.10%2.50M-0.46%Position as of Jun 30, 2026Filing date unknown
5
Invesco Ltd.
4.77%2.34M-6.84%Position as of Jun 30, 2026Filing date unknown
6
State Street Corporation
4.64%2.28M+4.28%Position as of Jun 30, 2026Filing date unknown
7
Geode Capital Management, LLC
2.43%1.20M-16.53%Position as of Jun 30, 2026Filing date unknown
8
Price (T.Rowe) Associates Inc
1.99%976.80K-22.66%Position as of Jun 30, 2026Filing date unknown
9
Franklin Resources, Inc.
1.65%811.97K-12.57%Position as of Jun 30, 2026Filing date unknown
10
Goldman Sachs Group Inc
1.59%780.65K+37.42%Position as of Jun 30, 2026Filing date unknown
Showing 10 of 10 matching institutional rows.

Recent insider transactions

Monolithic Power Systems (MPWR) Form 4 filings

Action codes are translated so open-market buys and sales are separate from awards, gifts, conversions, and tax withholding.

Monolithic Power Systems (MPWR) Form 4 insider transactions
#Insider% companyActionSharesTransaction date
1
TSENG SARIA H
General Counsel
<0.01%Stock GiftProvider-supplied Form 4 action code. Review the original filing before making a trading judgment.
Transaction context
Classification:
Gift
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

2.00KAug 31, 2026
2
CHANG KUO WEI HERBERT
Director
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

50Aug 24, 2026
3
DEAN ROBERT W II
Chief Financial Officer
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

32Aug 24, 2026
4
DEAN ROBERT W II
Chief Financial Officer
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

6Aug 17, 2026
5
CHANG KUO WEI HERBERT
Director
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

50Aug 11, 2026
6
DEAN ROBERT W II
Chief Financial Officer
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

105Aug 5, 2026
7
SCIAMMAS MAURICE
Officer
0.05%Stock GiftProvider-supplied Form 4 action code. Review the original filing before making a trading judgment.
Transaction context
Classification:
Gift
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

25.00KAug 4, 2026
8
SCIAMMAS MAURICE
Officer
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

30Aug 3, 2026
9
DEAN ROBERT W II
Chief Financial Officer
<0.01%Stock Award(Grant)Provider-supplied Form 4 action code. Review the original filing before making a trading judgment.
Transaction context
Classification:
Grant
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

1.36KJul 24, 2026
10
SCIAMMAS MAURICE
Officer
0.03%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

15.00KJul 15, 2026
11
SCIAMMAS MAURICE
Officer
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

30Jul 1, 2026
12
SCIAMMAS MAURICE
Officer
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

30Jun 1, 2026
Showing 12 of 120 matching Form 4 rows. Percent of company uses current shares outstanding.

Frequently asked

Common questions.

Who are the largest MPWR shareholders?

Blackrock Inc. is the largest reported institutional holder of MPWR, with 5.59 million shares, or about 11.37% of shares outstanding.

What does the institutional filing activity show for MPWR?

Monolithic Power Systems has 10 institutional rows on file: 4 increased or initiated positions and 6 reduced them.

What insider transactions are available for MPWR?

TECHi shows 120 dated MPWR insider transactions through Aug 31, 2026, with transaction types kept separate so administrative actions are not presented as open-market trades.

Are MPWR insiders buying or selling?

The displayed MPWR activity reads Net selling: 82 sales and 0 purchases. Other transaction types remain separate.

Who is the most active reported MPWR insider?

HSING MICHAEL R has the largest absolute share movement in the displayed MPWR filing rows, totaling 730,442 shares. The action labels provide the transaction context.

All data sources

Search the dated figures used for this view. Each entry identifies its units, reporting period and calculation status.

How to use this page

Use this to check who owns the float and whether insiders are active.

Best for Institutional concentration, insider transaction pattern, and float context.

Weak when Filings are delayed or transactions are administrative rather than economic.

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