Michael J. Desmarais - 27 Feb 2026 Form 4 Insider Report for COSTAR GROUP, INC. (CSGP)

Role
Chief Human Resources Officer
Signature
/s/ Gene Boxer, Attorney-in-Fact
Issuer symbol
CSGP
Transactions as of
27 Feb 2026
Net transactions value
-$283,534
Form type
4
Filing time
03 Mar 2026, 19:06:17 UTC
Previous filing
18 Mar 2025
Next filing
11 Mar 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
DESMARAIS MICHAEL J Chief Human Resources Officer C/O COSTAR GROUP, INC., 1201 WILSON BLVD., ARLINGTON /s/ Gene Boxer, Attorney-in-Fact 03 Mar 2026 0001925959

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction CSGP Common Stock, par value $0.01 per share Tax liability $283,534 -6,353 -8% $44.63 72,922 01 Mar 2026 Direct F1, F2

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction CSGP Restricted Stock Units Award $0 +17,926 $0.000000 17,926 27 Feb 2026 Common Stock, par value $0.01 per share 17,926 Direct F3, F4
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 On February 27, 2026, the last preceding business day, the closing price of the Company's common stock on Nasdaq was $44.63.
F2 Includes 157 shares acquired under the CoStar Group, Inc. Employee Stock Purchase Plan.
F3 Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock.
F4 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