MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2012

Aug 24, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2012-08-23

Reporting Person: CHANG KUO WEI HERBERT (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-08-23	Common Stock	M	3000.0	$20.2	Acquired	94035.0	Direct
2012-08-23	Common Stock	S	3000.0	$22.2667	Disposed	91035.0	Direct
2012-08-24	Common Stock	M	8500.0	$20.2	Acquired	99535.0	Direct
2012-08-24	Common Stock	S	8500.0	$22.3647	Disposed	91035.0	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-08-23	Non-Qualified Stock Option (right to buy)	$20.2	M	3000.0	Disposed	2017-02-09	Common Stock (3000.0)	Direct
2012-08-24	Non-Qualified Stock Option (right to buy)	$20.2	M	8500.0	Disposed	2017-02-09	Common Stock (8500.0)	Direct

Footnotes

F1: 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 $22.20 to $22.30. 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.

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 $22.20 to $22.60. 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.