ITEMS 1.01, 9.01

Company

COSTAR GROUP, INC.

Filed

April 28, 2011

Period of Report

April 27, 2011

Accession Number

0001057352-11-000069

An 8-K is a current report used to announce material events that shareholders should know about — such as earnings releases, mergers, executive changes, or bankruptcy. Learn more about 8-K filings →