Justices Won't Review Antitrust Counterclaims Against CoStar

By Matthew Perlman · March 23, 2026, 9:43 AM EDT

The U.S. Supreme Court refused on Monday to review a ruling that revived antitrust counterclaims lodged against the commercial real estate platform CoStar in its case accusing a rival platform of...

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Case Information

Case Title

CoStar Group, Inc. et al v. Commercial Real Estate Exchange Inc.

Case Number

2:20-cv-08819

Court

California Central

Nature of Suit

Copyright

Date Filed

September 25, 2020


Case Title

CoStar Group, Inc., et al., Petitioners v. Commercial Real Estate Exchange, Inc.

Case Number

25-667

Court

Supreme Court

Nature of Suit

3820 Copyright

Date Filed

December 08, 2025