0001057352-07-000092 8-K 1 20071129 1.01 2.03 20071129 20071129 COSTAR GROUP INC 0001057352 7389 522091509 1231 8-K 34 000-24531 071275521 2 BETHESDA METRO CENTER 10TH FLOOR BETHESDA MD 20814 3012158300 2 BETHESDA METRO CENTER 10TH FLOOR BETHESDA MD 20814 8-K 1 form_8k.htm CURRENT REPORT, ITEMS 1.01 AND 2.03