COSTAR GROUP, INC. — Director's Dealing 2013

Mar 13, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: COSTAR GROUP INC (CSGP)
CIK: 0001057352
Period of Report: 2013-03-11

Reporting Person: Kitchen Jennifer (Sr. Vice President, Research)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-03-11	Common Stock, par value $0.01 per share	A	3000	—	Acquired	27872	Direct
2013-03-12	Common Stock, par value $0.01 per share	F	402	$101.06	Disposed	27470	Direct
2013-03-13	Common Stock, par value $0.01 per share	M	7700	$42.29	Acquired	35170	Direct
2013-03-13	Common Stock, par value $0.01 per share	M	3933	$57.16	Acquired	39103	Direct
2013-03-13	Common Stock, par value $0.01 per share	M	1933	$58.95	Acquired	41036	Direct
2013-03-13	Common Stock, par value $0.01 per share	S	16066	$100.01	Disposed	24970	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-03-11	Option to Acquire Common Stock	$102.16	A	5100	Acquired	2023-03-10	Common Stock (5100)	Direct
2013-03-13	Option to Acquire Common Stock	$42.29	M	7700	Disposed	2020-03-11	Common Stock (7700)	Direct
2013-03-13	Option to Acquire Common Stock	$57.16	M	3933	Disposed	2021-03-03	Common Stock (3933)	Direct
2013-03-13	Option to Acquire Common Stock	$58.95	M	1933	Disposed	2022-02-20	Common Stock (1933)	Direct

Footnotes

F1: Represents all shares of Common Stock owned, consisting of 7,337 shares of Common Stock and 20,535 shares of Common Stock subject to unvested Restricted Stock Grants.

F2: Represents all shares of Common Stock owned, consisting of 8,102 shares of Common Stock and 19,368 shares of Common Stock subject to unvested Restricted Stock Grants.

F3: Represents all shares of Common Stock owned, consisting of 15,802 shares of Common Stock and 19,368 shares of Common Stock subject to unvested Restricted Stock Grants.

F4: Represents all shares of Common Stock owned, consisting of 19,735 shares of Common Stock and 19,368 shares of Common Stock subject to unvested Restricted Stock Grants.

F5: Represents all shares of Common Stock owned, consisting of 21,668 shares of Common Stock and 19,368 shares of Common Stock subject to unvested Restricted Stock Grants.

F6: Average based on sales prices ranging from $99.95 to $100.52.

F7: Represents all shares of Common Stock owned, consisting of 5,602 shares of Common Stock and 19,368 shares of Common Stock subject to unvested Restricted Stock Grants.

F8: The option vests in three equal installments on March 11, 2014, March 11, 2015, and March 11, 2016.

F9: The option vested in three equal installments on March 12, 2011, March 12, 2012, and March 12, 2013.

F10: The option vests in three equal installments on March 4, 2012, March 4, 2013, and March 4, 2014.

F11: The option vests in three equal installments on February 21, 2013, February 21, 2014, and February 21, 2015.