COSTAR GROUP INC

Ticker: CSGP CUSIP: 22160N109 Class: EQTY

MASON STREET ADVISORS, LLC's Holding History (CIK: 0001167711)

Note: Option positions (PUT/CALL) are excluded.

Q4 2014

Shares 170,547 Value ($000) $31,318 Avg Close $16.16 Range $13.44 - $18.96

Q3 2014

Shares 140,585 Value ($000) $21,867 Avg Close $14.90 Range $13.85 - $16.58

Q2 2014

Shares 153,333 Value ($000) $24,253 Avg Close $16.20 Range $14.70 - $19.34

Q1 2014

Shares 136,423 Value ($000) $25,476 Avg Close $18.86 Range $16.38 - $21.82

Q4 2013

Shares 89,788 Value ($000) $16,573 Avg Close $17.69 Range $16.07 - $18.84

Q3 2013

Shares 96,385 Value ($000) $16,183 Avg Close $15.34 Range $12.98 - $17.22

Period	Shares	Value ($000)	Average Close	Price Range
Q4 2014	170,547	$31,318	$16.16	$13.44 - $18.96
Q3 2014	140,585	$21,867	$14.90	$13.85 - $16.58
Q2 2014	153,333	$24,253	$16.20	$14.70 - $19.34
Q1 2014	136,423	$25,476	$18.86	$16.38 - $21.82
Q4 2013	89,788	$16,573	$17.69	$16.07 - $18.84
Q3 2013	96,385	$16,183	$15.34	$12.98 - $17.22