CoStar (CSGP) CAO granted 6,834 RSUs and withholds shares for taxes

Rhea-AI Filing Summary

CoStar Group Chief Accounting Officer Cynthia Cammett reported routine equity compensation activity. She received a grant of 6,834 restricted stock units, each representing the right to receive one share of CoStar common stock, with no purchase price.

The restricted stock units vest in four equal installments on March 1, 2027, 2028, 2029, and 2030. In a separate transaction, 1,385 shares of common stock were withheld at a price of $44.63 per share to cover tax obligations, leaving her with 21,968 common shares held directly, including 142 shares acquired under the employee stock purchase plan.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Cann Cynthia Cammett

Role Chief Accounting Officer

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock, par value $0.01 per share	1,385	$44.63	$62K
Grant/Award	Restricted Stock Units	6,834	$0.00	--

Holdings After Transaction: Common Stock, par value $0.01 per share — 21,968 shares (Direct); Restricted Stock Units — 6,834 shares (Direct)

Footnotes (1)

1. On February 27, 2026, the last preceding business day, the closing price of the Company's common stock on Nasdaq was $44.63. Includes 142 shares acquired under the CoStar Group, Inc. Employee Stock Purchase Plan. Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock. The restricted stock units vest in four equal installments on March 1, 2027, March 1, 2028, March 1, 2029, and March 1, 2030.

Form 4 Insider Transactions: What Each Field Means →

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^*

Cann Cynthia Cammett

(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)
	Chief Accounting Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/27/2026

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	03/01/2026		F		1,385	D	$44.63(1)	21,968(2)	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
Restricted Stock Units	(3)	02/27/2026		A		6,834		(4)	(4)	Common Stock, par value $0.01 per share	6,834	$0	6,834	D

Explanation of Responses:

1. On February 27, 2026, the last preceding business day, the closing price of the Company's common stock on Nasdaq was $44.63.

2. Includes 142 shares acquired under the CoStar Group, Inc. Employee Stock Purchase Plan.

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

4. The restricted stock units vest in four equal installments on March 1, 2027, March 1, 2028, March 1, 2029, and March 1, 2030.

Remarks:

Exhibit 24 - Power of Attorney

	/s/ Gene Boxer, Attorney-in-Fact	03/03/2026
	** 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.

FAQ

What equity award did CoStar (CSGP) executive Cynthia Cammett receive?

Cynthia Cammett received a grant of 6,834 restricted stock units. Each unit represents a contingent right to receive one share of CoStar common stock, providing long-term, stock-based compensation tied directly to the company’s share performance over several years.

How do Cynthia Cammett’s new restricted stock units at CoStar (CSGP) vest?

The 6,834 restricted stock units vest in four equal installments. Vesting dates are March 1, 2027, March 1, 2028, March 1, 2029, and March 1, 2030, encouraging long-term retention and alignment with CoStar’s multi-year performance.

Why were 1,385 CoStar (CSGP) shares disposed of by Cynthia Cammett?

The 1,385 shares were not open-market sales but a tax-withholding disposition. Shares were delivered back to the company to satisfy tax obligations related to equity compensation, using a share value of $44.63 per share based on the Nasdaq closing price.

How many CoStar (CSGP) shares does Cynthia Cammett hold after these transactions?

After the tax-withholding transaction, Cynthia Cammett holds 21,968 shares of CoStar common stock directly. This total includes 142 shares that were acquired through the CoStar Group, Inc. Employee Stock Purchase Plan, reflecting ongoing participation in company equity.

What does each restricted stock unit represent in CoStar (CSGP)’s Form 4 filing?

Each restricted stock unit represents a contingent right to one share of CoStar common stock. The units convert into actual shares only upon vesting on the scheduled dates, aligning executive compensation with future service and company performance over time.

How was the $44.63 per share price determined for CoStar (CSGP) tax withholding?

The $44.63 per share value used for the 1,385-share tax withholding was the Nasdaq closing price of CoStar’s common stock on February 27, 2026, the last preceding business day before the tax-withholding disposition on March 1, 2026.