MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2014

May 6, 2014

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2014-05-02

Reporting Person: Sciammas Maurice (Sr. V.P.of Sales and Marketing)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2014-05-02	Common Stock	S	1696.0	$36.7695	Disposed	92076	Direct
2014-05-05	Common Stock	S	312.0	$36.25	Disposed	91764	Direct
2014-05-05	Common Stock	S	400.0	$36.82	Disposed	91364	Direct
2014-05-05	Common Stock	S	798.0	$36.8201	Disposed	90566	Direct
2014-05-05	Common Stock	S	331.0	$36.2501	Disposed	90235	Direct
2014-05-05	Common Stock	S	17.0	$36.25	Disposed	90218	Direct
2014-05-05	Common Stock	S	724.0	$36.2501	Disposed	89494	Direct
2014-05-06	Common Stock	S	307.0	$36.41	Disposed	89187	Direct
2014-05-06	Common Stock	S	701.0	$36.4106	Disposed	88486	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	2000	Indirect

Footnotes

F1: Shares sold to pay tax obligations resulting from the vesting of restricted stock units.

F2: In accordance with the reporting person's 10b5-1 trading plan.