CoStar Group HR chief acquires 12,805 stock units

The units vest in three equal annual installments on November 15, 2027, November 15, 2028, and November 15, 2029.

Available on EDGAR 11/10/2026 - 05:46 PM EST Accepted by SEC EDGAR 11/10/2026 - 05:45 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

CoStar Group, Inc. (CSGP) reports that Chief Human Resources Officer Catrina Harding acquired 12,805 restricted stock units on November 9, 2026. Her reported direct post-transaction position was 12,805 restricted stock units. Each unit represents a contingent right to receive one share of common stock, and the units vest in three equal annual installments on November 15, 2027, November 15, 2028, and November 15, 2029.

Insider Trade Summary

Grant/Award: 12,805 shares

Grant/Award 1 txn

Insider Harding Catrina

Role Chief Human Resources Officer

Type	Security	Shares	Price	Value
Grant/Award	Restricted Stock Units F1, F2	12,805	$0.00	$0.00

Holdings After Transaction: Restricted Stock Units — 12,805 units (Direct)

Footnotes (2)

1. F1. Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock.
2. F2. The restricted stock units vest in three equal annual installments on November 15, 2027, November 15, 2028, and November 15, 2029.

Key Figures

Restricted stock units acquired: 12,805 restricted stock units Direct post-transaction position: 12,805 restricted stock units Common shares represented per unit: 1 common share +4 more

7 metrics

Restricted stock units acquired 12,805 restricted stock units November 9, 2026

Direct post-transaction position 12,805 restricted stock units After the November 9, 2026 transaction

Common shares represented per unit 1 common share Each restricted stock unit represents a contingent right to receive one share

Vesting installments 3 equal annual installments Restricted stock units

First vesting date November 15, 2027 Restricted stock units

Second vesting date November 15, 2028 Restricted stock units

Third vesting date November 15, 2029 Restricted stock units

Key Terms

restricted stock units, contingent right, vest

3 terms

restricted stock units financial

"The restricted stock units vest in three equal annual installments"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

contingent right financial

"a contingent right to receive one share"

vest financial

"The restricted stock units vest in three equal annual installments"

A vest is the process by which an employee earns the right to receive certain benefits or ownership interests, such as stock or retirement funds, over time. It’s similar to earning a reward gradually, ensuring that the benefit becomes fully yours only after a set period or meeting specific conditions. This makes it important for investors because it determines when they can actually claim or use those benefits.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many CSGP restricted stock units did Catrina Harding acquire?

Catrina Harding acquired 12,805 restricted stock units on November 9, 2026. Her reported direct post-transaction position was 12,805 restricted stock units.

When do Catrina Harding’s CSGP restricted stock units vest?

The units vest in three equal annual installments on November 15, 2027, November 15, 2028, and November 15, 2029.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

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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^*

Harding Catrina

(Last) (First) (Middle)

1201 WILSON BOULEVARD

(Street)

ARLINGTON VIRGINIA 22209

(City) (State) (Zip)

UNITED STATES

(Country)

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)
	Chief Human Resources Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
11/09/2026

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

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

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

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

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
Restricted Stock Units	(1)	11/09/2026		A		12,805		(2)	(2)	Common Stock, par value $0.01 per share	0	$0	12,805	D

Explanation of Responses:

1. Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock.

2. The restricted stock units vest in three equal annual installments on November 15, 2027, November 15, 2028, and November 15, 2029.

Remarks:

	/s/ Lisa M. Tanzi, Attorney-in-Fact for Catrina Harding	11/10/2026
	** 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.
* Form 4: SEC 1474 (03-26)