MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2012

Aug 10, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2012-08-09

Reporting Person: Xiao Deming (Pres. of MPS Asia Operations)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-08-09	Common Stock	S	1915.0	$20.46	Disposed	126986.0	Direct
2012-08-10	Common Stock	S	1786.0	$20.7344	Disposed	125200.0	Direct
2012-08-09	Common Stock	M	12108.0	$8.05	Acquired	22108.0	Indirect
2012-08-09	Common Stock	S	12108.0	$20.9	Disposed	10000.0	Indirect
2012-08-09	Common Stock	M	14329.0	$8.05	Acquired	24329.0	Indirect
2012-08-09	Common Stock	S	14329.0	$20.9	Disposed	10000.0	Indirect

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-08-09	Incentive Stock Option (right to buy)	$8.05	M	41329.0	Disposed	2015-04-26	Common Stock (41329.0)	Indirect
2012-08-09	Non-Qualified Stock Option (right to buy)	$8.05	M	12108.0	Disposed	2015-04-26	Common Stock (12108.0)	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.