MPWR Filing
4Filing Date: May 20, 2026
MONOLITHIC POWER SYSTEMS INC (MPWR) · Insider Trading (Form 4) SEC Filing
Statement of Changes in Beneficial Ownership
descriptionView SEC Filing
ACC: 0001214659-26-006622open_in_new
Total Value$6.3K
Trades2
Insiders1
Transaction Details
DEAN ROBERT W II
Interim CFO·Direct
Sell · Dispose
Common Stock
Shares-4
Price$1563.28
Total Value$6.3K
Shares Owned After5.90K
Transaction DateMay 18, 2026
Footnotes ▸
The reported sale was to cover tax withholding obligations upon the vesting of restricted stock units.
DEAN ROBERT W II
Interim CFO·Indirect · Held by Parent & Daughter
Common Stock
Shares0
Price-
Total Value$0
Shares Owned After65
Post-Transaction Holdings
DEAN ROBERT W II
| Security | Shares | Change |
|---|---|---|
| Common Stock | 5.96K | -4 (-0.07%) |
Original SEC Filing Textexpand_more
=== SEC Form 4 — Statement of Changes in Beneficial Ownership ===
Document Type: 4
Period of Report: 2026-05-18
10b5-1 Pre-arranged Plan: No
--- Issuer ---
Name: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
--- Reporting Owner ---
Name: DEAN ROBERT W II
CIK: 0001445300
Role: Officer (Interim CFO)
--- Non-Derivative Transactions ---
[Transaction #1]
Security: Common Stock
Date: 2026-05-18 | Code: S (Open market sale)
Shares: -4 | Price: $1,563.28
Total Value: $6,253.12
Shares Owned After: 5,900 | Ownership: D (Direct)
Footnotes:
[F1] The reported sale was to cover tax withholding obligations upon the vesting of restricted stock units.
--- Holdings ---
[Holding #1]
Security: Common Stock
Ownership: I (Indirect)
--- Footnotes (Complete Index) ---
F1: The reported sale was to cover tax withholding obligations upon the vesting of restricted stock units.
--- Signature ---
/s/ /s/ Saria Tseng, attorney-in-fact for Mr. Robert W. Dean II (2026-05-20)