Mr. Robert W. Dean II - 24 Aug 2026 Form 4 Insider Report for MONOLITHIC POWER SYSTEMS, INC. (MPWR)

Reporting relationship: Interim CFO
Issuer ticker: MPWR
Reported as of: 24 Aug 2026
Net transaction value: -$41,527
SEC form: 4
Accepted by SEC: 26 Aug 2026, 19:22:23 UTC
Prior SEC filing: 19 Aug 2026
Source filing: View source filing
Reporting owner signature: /s/ Saria Tseng, attorney-in-fact for Mr. Robert W. Dean II

Key filing fact

Mr. Robert W. Dean II filed Form 4 for MONOLITHIC POWER SYSTEMS, INC. (MPWR) on 26 Aug 2026.

Key facts

This page summarizes Mr. Robert W. Dean II's Form 4 filing for MONOLITHIC POWER SYSTEMS, INC. (MPWR).
2 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 26 Aug 2026, 19:22.

Change

Previous filing in this sequence was filed on 19 Aug 2026.
Current net transaction value: -$41,527.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001445300 Primary reporting owner

DEAN ROBERT W II

Relationship: Interim CFO
Address: 1555 PALM BEACH LAKES BLVD., WEST PALM BEACH
Signature: /s/ Saria Tseng, attorney-in-fact for Mr. Robert W. Dean II
Signature date: 26 Aug 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

MPWR transaction

Common Stock

Sale

Transaction value: $41,527
Shares: -32
Change %: -0.45%
Price: $1297.72
Shares after: 7,094
Date: 24 Aug 2026
Ownership: Direct
Footnotes: F1, F2

MPWR transaction

Common Stock

Other

Transaction value
Shares: -5
Change %: -0.07%
Price: $0.000000^*
Shares after: 7,089
Date: 24 Aug 2026
Ownership: Direct
Footnotes: F3

MPWR holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 65
Date: 24 Aug 2026
Ownership: Held by Parent & Daughter

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

The reported sale was to cover tax withholding obligations upon the vesting of restricted stock units.

Footnote F2

The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,296.07 to $1,298.01. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

Footnote F3

The reported transaction involved a transfer of securities from the reporting person's direct holdings to an individual who is not an immediate family member sharing the same household. No funds were exchanged and no sale of shares occurred in the transfer. Following the completion of the transfer, the reporting person no longer retains any pecuniary interest in the shares.