Sec Form 3 Filing - SIMURO FRANK @ COSTAR GROUP, INC. - 2022-04-18

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person SIMURO FRANK 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 Technology Officer (Last) (First) (Middle) C/O COSTAR GROUP, INC., 1331 L STREET NW 3. Date of Earliest Transaction (MM/DD/YY) 04/18/2022 (Street) WASHINGTON, DC20005 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 276,602( 1 ) 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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: 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 Option to Acquire Common Stock $ 10.22 ( 2 ) 03/10/2023 Common Stock 35,220 D Option to Acquire Common Stock $ 19.37 ( 3 ) 03/04/2025 Common Stock 10,320 D Option to Acquire Common Stock $ 18.28 03/11/2019 03/10/2026 Common Stock 5,470 D Option to Acquire Common Stock $ 20.49 03/31/2020 03/01/2027 Common Stock 4,880 D Option to Acquire Common Stock $ 34.21 ( 4 ) 02/27/2028 Common Stock 25,340 D Option to Acquire Common Stock $ 39.82 ( 5 ) 02/06/2029 Common Stock 38,000 D Option to Acquire Common Stock $ 66.65 ( 6 ) 02/05/2030 Common Stock 33,000 D Option to Acquire Common Stock $ 91.98 ( 7 ) 02/17/2031 Common Stock 17,000 D Option to Acquire Common Stock $ 67.29 ( 8 ) 02/15/2032 Common Stock 22,600 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other SIMURO FRANK C/O COSTAR GROUP, INC. 1331 L STREET NW WASHINGTON, DC20005 Chief Technology Officer Signatures /s/ Michael Rosenthall, Attorney-in-Fact 04/28/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents all shares of Common Stock owned, consisting of 116,510 shares of Common Stock and 110,150 shares of Common Stock subject to unvested Restricted Stock grants, 24,971 shares of Deferred Stock Units and 24,971 shares of unvested Restricted Stock Units. ( 2 )The option, representing a right to purchase 125,220 shares, became exercisable as to 45,000 shares on March 11, 2014, 45,000 shares on March 11, 2015, and 35,220 shares on March 11, 2016. ( 3 )The option became exercisable in equal installments on March 5, 2017 and March 5, 2018. ( 4 )The option, representing a right to purchase 76,000 shares, became exercisable as to 25,330 shares on February 28, 2019, 25,330 shares on February 28, 2020, and 25,340 shares on February 28, 2021. ( 5 )The option, representing a right to purchase 38,000 shares, became exercisable as to 12,660 shares on February 15, 2020, 12,670 shares on February 15, 2021, and 12,670 shares on February 15, 2022. ( 6 )The option, representing a right to purchase 33,000 shares, became exercisable as to 11,000 shares on February 15, 2021 and 11,000 shares on February 15, 2022, and becomes exercisable as to 11,000 shares on February 15, 2023. ( 7 )The option, representing a right to purchase 17,000 shares, became exercisable as to 5,660 shares on March 1, 2022, and becomes exercisable as to 5,670 shares on March 1, 2023 and 5,670 shares on March 1, 2024. ( 8 )The option, representing a right to purchase 22,600 shares, becomes exercisable as to 7,533 shares on March 1, 2023, 7,533 shares on March 1, 2024, and 7,534 shares on March 1, 2025.

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).

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