MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2013

Jul 18, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2013-07-16

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-07-16	Common Stock	M	23450.0	$14.89	Acquired	128330	Direct
2013-07-16	Common Stock	M	28703.0	$15.03	Acquired	157033	Direct
2013-07-16	Common Stock	S	23450.0	$26.0004	Disposed	133583	Direct
2013-07-16	Common Stock	S	28703.0	$26.001	Disposed	104880	Direct
2013-07-16	Common Stock	S	9073.0	$25.7699	Disposed	95807	Direct
2013-07-17	Common Stock	M	61297.0	$15.03	Acquired	157104	Direct
2013-07-17	Common Stock	S	61297.0	$26.0848	Disposed	95807	Direct
2013-07-17	Common Stock	S	11636.0	$26.1151	Disposed	84171	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-07-16	Non-Qualified Stock Option (right to buy)	$15.6	M	23450.0	Disposed	2015-02-08	Common Stock (23450)	Direct
2013-07-16	Non-Qualified Stock Option (right to buy)	$15.74	M	28703.0	Disposed	2015-10-28	Common Stock (28703)	Direct
2013-07-17	Non-Qualified Stock Option (right to buy)	$15.74	M	61297.0	Disposed	2015-10-28	Common Stock (61297)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	12033	Indirect

Footnotes

F1: In accordance with the reporting person's 10b5-1 trading plan.

F2: On December 11, 2012, the Company's Board declared a special cash dividend of $1.00 per common share, which was paid on December 28, 2012 to all shareholders of record as of the close of business on December 21, 2012. The Board approved a modification whereby each outstanding option as of December 28, 2012 was increased by a ratio of 1.0471 with a corresponding reduction in the exercise 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 $26.00 to $26.01. 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 $25.60 to $25.9136. 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 $26.00 to $26.25. 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 $26.01 to $26.2050. 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.