[Form 4] CoStar Group Inc Insider Trading Activity

Rhea-AI Filing Summary

Dropbox, Inc. (ticker: DBX) filed a Form 4 on 2 July 2025 reporting two open-market sales of Class A common stock by Chief Financial Officer Timothy Regan.

• Transaction dates & volumes: 2,500 shares sold on 30 Jun 2025 at $28.40; 10,000 shares sold on 1 Jul 2025 at a weighted-average $27.9392.
• Total shares sold: 12,500, representing approximately 2.4 % of the executive’s post-sale holdings.
• Remaining ownership: 516,094 Class A shares held directly.
• Trading plan: All sales executed under a Rule 10b5-1 plan adopted on 15 May 2024, indicating pre-arranged, schedule-based transactions.
• Equity mix: Remaining position includes restricted stock awards/units that vest through 15 Feb 2029; any unvested awards cancel if employment ends.

The filing discloses no derivative transactions and contains no indication of additional insider participation. While insider sales can be perceived negatively, the modest size relative to Regan’s continuing stake and the existence of a 10b5-1 plan mitigate potential signaling risk. No operational or financial performance metrics were provided in this document.

Positive

• Rule 10b5-1 plan in place reduces chance of opportunistic trading and signals adherence to compliance best practices.
• CFO retains a large 516,094-share stake, maintaining alignment with shareholder interests.

Negative

• Insider sale by CFO can be interpreted as reduced confidence, even if modest.
• No offsetting insider purchases or operational disclosures provided to counter potential negative sentiment.

Insights

Sell-Side Equity Analyst

TL;DR: CFO’s 12.5k share sale (~$0.35 m) is small relative to >500k holdings; neutral signal given pre-arranged 10b5-1 plan.

From a valuation perspective, this disposition equates to roughly two trading days of average DBX volume and only ~2 % of the executive’s stake, limiting informational content. The continuing 516 k share position plus multi-year RSU vesting indicates sustained alignment with shareholders. I view the transaction as routine portfolio diversification, not a thesis-altering event.

Corporate Governance Specialist

TL;DR: Insider sale by a key officer is modest but still a mildly negative governance datapoint.

Even with 10b5-1 protection, market participants often discount insider selling by C-suite executives. The filing offers transparency on plan adoption and weighted-average pricing, but lacks detail on motive or future intent. Given insider trading research linking sequential sales to underperformance, I assign a slight negative governance bias, though magnitude is limited by the executive’s residual ownership.

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^*

LOWN CHRISTIAN M.

(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 Financial Officer

3. Date of Earliest Transaction (Month/Day/Year)
07/01/2025

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	07/01/2025		F		4,666	D	$80.4	130,157	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

Explanation of Responses:

Remarks:

	/s/ Gene Boxer, Attorney-in-Fact	07/02/2025
	** 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

How many Dropbox (DBX) shares did the CFO sell?

12,500 Class A shares were sold across two days: 2,500 on 06/30/25 and 10,000 on 07/01/25.

What was the average sale price of the DBX shares?

Shares were sold at $28.40 and a weighted-average $27.9392, respectively.

Does the CFO still hold Dropbox stock after the sale?

Yes. 516,094 shares of Class A common stock remain in his direct ownership.

Was the sale conducted under a trading plan?

Yes, both transactions were executed under a Rule 10b5-1 plan adopted on 15 May 2024.

Did the filing disclose any derivative transactions?

No. Table II shows no derivative activity; only open-market sales of common stock were reported.

What happens to the CFO’s unvested RSUs if he leaves Dropbox?

Any unvested restricted stock awards/units will be cancelled upon termination of service.