CoStar Group (CSGP)Baron Capital Group, Inc. now owns 5.3% of CSGP as a passive investor 5.3%

5.3%

Stake

21.6M

Shares owned

Stake as of

Jun 30, 2026

Filed

Aug 14, 2026

The story around this disclosure

Every dated public record OQRO holds about the company from 60 days before to 120 days after, oldest first. It shows what was going on; none of it is a stated reason for the trade.

1. Apr 14, 2026CongressDisclosed partial sale of CSGP — reported range $1,001 - $15,000
2. May 1, 2026Insider · 1 personInsiders: 2 purchases (~$2.5M)
3. May 28, 2026Company filing · Form 8-K · Material agreement, Reg FDSigned an important agreement, and shared information with investors
4. Jun 23, 2026Company filing · Form 8-K · Executive change, Shareholder voteChanged a top executive or board member, and held a shareholder vote (and 1 more item)“On June 23, 2026, at the Annual Meeting of Stockholders (the “Annual Meeting”) of CoStar Group, Inc. (the “Company” or “our”), the stockholders of the Company, upon the recommendation of the Board of Directors of the Company (the “Board”), approved the CoStar Group, Inc. 2026 Employee Stock Purchase Plan (the “2026 ESPP”), which was approved by the Board on April 27, 2026 and became effective upon stockholder…”

What came next

1. Jul 7, 2026Company filing · Form 8-K · Executive change, Reg FDChanged a top executive or board member, and shared information with investors“On July 13, 2026, the Board of Directors (the “Board”) of CoStar Group, Inc. (the “Company” or “CoStar Group”) appointed Robin Rossmann to serve as the Company’s Chief Financial Officer, effective July 31, 2026 (“Effective Date”).”
2. Jul 28, 2026Company filing · Form 8-K · ResultsReported its results
3. Aug 4, 2026InsiderCEO purchased ~$2.49M of CSGP shares in the open market
4. Aug 5, 2026InsiderDirector sold ~$106K of CSGP shares in the open market
5. Aug 7, 2026InsiderOfficer sold ~$147K of CSGP shares in the open market
6. Aug 14, 20265% stakeBaron Capital Group, Inc. reported a passive stake (13G) of 5.3%
7. Aug 19, 2026CongressDisclosed purchase of CSGP — reported range $1,001 - $15,000

How to read SEC Schedule 13G

A Schedule 13D and a Schedule 13G both disclose beneficial ownership of more than 5% of a US company's voting shares. A 13D is the long form, filed by holders who may seek to influence or control the company, and it must state what they intend to do. A 13G is the short form, open only to passive holders and to certain institutions holding in the ordinary course of business, and it asks no question about intent.

Full guide: Schedule 13D vs Schedule 13G: what is the difference?

What else is on file for CoStar Group

For CoStar Group, OQRO holds 3 insider filings (SEC Form 4 or Form 144), 1 Congress trade report and 19 fund holdings reports (13F) dated in the last 90 days.

These are records OQRO holds, counted by their date, not a measure of how much trading took place. Routine paperwork such as option exercises and tax withholding is left out. Everything for the company is on its CSGP page.

How this filing works

• Schedule 13D vs 13G

Other disclosures at CoStar Group

• House Clerk periodic transaction reportSep 10, 2026
• SEC Form 13F-HRAug 14, 2026
• SEC Form 13F-HRAug 14, 2026
• SEC Form 13F-HRAug 14, 2026
• SEC Form 13F-HRAug 14, 2026
• SEC Form 13F-HRAug 14, 2026

Everything OQRO holds on this company is on its CSGP page.