[Form 4] CoStar Group Inc Insider Trading Activity

Rhea-AI Filing Summary

Saint Frederick G., an officer serving as President, Marketplaces at CoStar Group, Inc. (CSGP), reported a non-derivative transaction in the issuer's common stock dated 08/01/2025. The report shows a disposition of 1,436 shares at a price of $95.19, leaving beneficial ownership of 318,103 shares held directly. No derivative positions are listed.

Positive

• Insider transaction was disclosed through a Form 4, updating public records of beneficial ownership
• No derivative securities are reported in Table II, simplifying the ownership picture

Negative

• Reporting person disposed of 1,436 shares (transaction listed at $95.19) which reduces insider holdings
• No explanatory remarks accompany the transaction, so the reason for the transfer is not provided in the filing

Insights

Financial Analyst

TL;DR: Insider reported a small direct sale leaving 318,103 shares outstanding for the insider.

The Form 4 shows a single non-derivative transaction: a reported disposition of 1,436 CoStar (CSGP) common shares at $95.19, leaving the reporting person with 318,103 shares held directly. No derivative instruments were reported, and the filing contains no explanatory remarks. Given the absolute size reported, this transaction appears immaterial to overall ownership absent additional context.

Corporate Governance Expert

TL;DR: Proper Section 16 disclosure was filed, showing a direct change in insider holdings with no additional commentary.

The filing identifies the reporting person as an officer (President, Marketplaces) and discloses a change in beneficial ownership via common stock. The filing includes transaction code F and reports post-transaction direct ownership of 318,103 shares. The form contains no remarks explaining the transaction, which limits insight into the rationale behind the transfer.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

SAINT FREDERICK G.

(Last) (First) (Middle)

C/O COSTAR GROUP, INC.

1201 WILSON BLVD.

(Street)

ARLINGTON VA 22209

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
COSTAR GROUP, INC. [ CSGP ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President, Marketplaces

3. Date of Earliest Transaction (Month/Day/Year)
08/01/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $0.01 per share	08/01/2025		F		1,436	D	$95.19	318,103	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

Remarks:

	/s/ Gene Boxer, Attorney-in-Fact	08/05/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What transaction did the CoStar (CSGP) insider report?

The insider reported a non-derivative transaction disposing of 1,436 shares of CoStar common stock.

At what price were the CSGP shares reported on the Form 4?

The transaction is reported at a price of $95.19 per share.

How many CoStar (CSGP) shares does the reporting person own after the transaction?

The Form 4 shows beneficial ownership of 318,103 shares following the reported transaction.

What is the reporting person's role at CoStar Group (CSGP)?

The reporting person is listed as an Officer with the title President, Marketplaces.

Are any derivative securities reported in this Form 4 for CSGP?

No. Table II lists no derivative securities; only a non-derivative common stock transaction is reported.