CoStar (CSGP) GC awarded 26,888 RSUs, 4,547 shares withheld

Rhea-AI Filing Summary

CoStar Group General Counsel and Secretary Gene Boxer reported two equity-related transactions. He received 26,888 restricted stock units on February 27, 2026, each representing one share of common stock. These RSUs vest in three equal installments on March 1, 2027, 2028 and 2029.

On March 1, 2026, Boxer had 4,547 shares of common stock disposed in a tax-withholding transaction at $44.63 per share, corresponding to the prior Nasdaq closing price. After this, he directly owned 74,025 common shares and 26,888 RSUs.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Boxer Gene

Role General Counsel and Secretary

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock, par value $0.01 per share	4,547	$44.63	$203K
Grant/Award	Restricted Stock Units	26,888	$0.00	--

Holdings After Transaction: Common Stock, par value $0.01 per share — 74,025 shares (Direct); Restricted Stock Units — 26,888 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. Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock. The restricted stock units vest in three equal installments on March 1, 2027, March 1, 2028 and March 1, 2029.

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^*

Boxer Gene

(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)
	General Counsel and Secretary

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		4,547	D	$44.63(1)	74,025	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	(2)	02/27/2026		A		26,888		(3)	(3)	Common Stock, par value $0.01 per share	26,888	$0	26,888	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. Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock.

3. The restricted stock units vest in three equal installments on March 1, 2027, March 1, 2028 and March 1, 2029.

Remarks:

Exhibit 24 - Power of Attorney

	/s/ Gene Boxer	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 insider transactions did CoStar (CSGP) executive Gene Boxer report?

Gene Boxer reported a grant of 26,888 restricted stock units and a tax-withholding disposition of 4,547 common shares. The disposition used a share price of $44.63, matching CoStar’s Nasdaq closing price on February 27, 2026 for tax calculation purposes.

How many restricted stock units did Gene Boxer receive from CoStar (CSGP)?

Gene Boxer received 26,888 restricted stock units. Each RSU represents a contingent right to one share of CoStar Group common stock. The award increases his potential future equity stake, subject to the vesting schedule running from 2027 through 2029 if service conditions are met.

What is the vesting schedule for Gene Boxer’s new CoStar (CSGP) RSUs?

The 26,888 RSUs vest in three equal installments. One-third vests on March 1, 2027, another third on March 1, 2028, and the final third on March 1, 2029, aligning the executive’s compensation with multi-year company performance and retention.

Why were 4,547 CoStar (CSGP) shares disposed of in Gene Boxer’s Form 4?

The 4,547 common shares were disposed of in a tax-withholding transaction, not an open-market sale. This transaction (code F) reflects payment of tax liabilities by delivering shares, using a price of $44.63 based on the prior Nasdaq closing price.

How many CoStar (CSGP) shares does Gene Boxer hold after these transactions?

After the reported transactions, Gene Boxer directly owns 74,025 shares of CoStar common stock and holds 26,888 restricted stock units. The RSUs represent additional potential shares that may be delivered if the time-based vesting conditions through 2029 are satisfied.

What does transaction code F mean in Gene Boxer’s CoStar (CSGP) Form 4?

Transaction code F indicates a payment of tax liability by delivering securities. In this case, 4,547 CoStar common shares were used to satisfy taxes due, rather than being sold in the open market, at a reference price of $44.63 per share.