MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2026

Jan 6, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2026-01-02

Reporting Person: BLEGEN THEODORE (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2026-01-02	Common Stock	S	80	$927.61	Disposed	71252	Direct
2026-01-02	Common Stock	S	194	$930.86	Disposed	71058	Direct
2026-01-02	Common Stock	S	80	$933.64	Disposed	70978	Direct
2026-01-02	Common Stock	S	40	$934.74	Disposed	70938	Direct
2026-01-02	Common Stock	S	80	$935.33	Disposed	70858	Direct
2026-01-02	Common Stock	S	120	$936.50	Disposed	70738	Direct
2026-01-02	Common Stock	S	460	$938.52	Disposed	70278	Direct
2026-01-02	Common Stock	S	117	$939.75	Disposed	70161	Direct
2026-01-02	Common Stock	S	40	$940.03	Disposed	70121	Direct
2026-01-02	Common Stock	S	406	$941.60	Disposed	69715	Direct
2026-01-02	Common Stock	S	74	$942.42	Disposed	69641	Direct
2026-01-02	Common Stock	S	539	$943.71	Disposed	69102	Direct
2026-01-02	Common Stock	S	650	$944.35	Disposed	68452	Direct
2026-01-02	Common Stock	S	40	$945.00	Disposed	68412	Direct
2026-01-02	Common Stock	S	80	$946.62	Disposed	68332	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	5331	Indirect
Common Stock	5331	Indirect

Footnotes

F1: These transactions were made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 2/26/2025.

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 $935.08 to $935.57. 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.

F3: 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 $938.14 to $938.69. 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.

F4: 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 $939.51 to $939.99. 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.

F5: 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 $941.00 to $941.67. 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.

F6: 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 $942.01 to $942.77. 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.

F7: 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 $943.37 to $943.85. 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.

F8: 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 $944.01 to $944.51. 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.