[Form 4] Greenidge Generation Holdings Inc. Insider Trading Activity

Rhea-AI Filing Summary

Christian Mulvihill, identified as the Chief Financial Officer of Greenidge Generation Holdings Inc., reported two non-discretionary sales on 09/16/2025 to cover tax withholding related to the vesting of restricted stock units. The Form 4 shows sales at prices of $1.47 and $1.46. Following the reported transactions, the reporting person beneficially owned 98,640 and 98,018 shares respectively as shown on separate reporting lines. The filing is signed on 09/17/2025 and includes an explicit statement that the disposals were made solely to satisfy tax withholding obligations and were not discretionary sales.

Positive

• Clear disclosure that the sales were to satisfy tax withholding for vested restricted stock units
• Form signed and filed promptly (dated 09/17/2025) indicating compliance with Section 16 reporting

Negative

• None.

Insights

Financial Analyst

TL;DR: Routine insider share sales to cover RSU tax withholding; no indication of discretionary selling or change to ownership control.

The Form 4 documents two small sales by the CFO on 09/16/2025 at $1.47 and $1.46 per share explicitly to satisfy tax withholding for vested restricted stock units. The filing lists the post-transaction beneficial ownership figures of 98,640 and 98,018 shares on separate lines, consistent with withholding settlements rather than open-market disposals. This activity is administrative and does not, based on the filing, signal a shift in executive stake or control.

Corporate Governance Expert

TL;DR: Disclosure aligns with Section 16 reporting requirements and clarifies the non-discretionary nature of the transactions.

The Form 4 is properly executed and signed, shows the reporting person as an officer (Chief Financial Officer), and provides an explanatory remark that the sales were to cover tax withholding for RSU vesting. From a governance and compliance perspective, this is routine Section 16 reporting that documents compensation-related share settlements and preserves transparency for investors and regulators.

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).

1. Name and Address of Reporting Person^*

Mulvihill Christian

(Last) (First) (Middle)

C/O GREENIDGE GENERATION HOLDINGS INC.

1159 PITTSFORD-VICTOR ROAD, SUITE 240

(Street)

PITTSFORD NY 14534

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Greenidge Generation Holdings Inc. [ GREE ]

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)
09/16/2025

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
Class A Common Stock	09/16/2025(1)		S		5	D	$1.47	98,640	D
Class A Common Stock	09/16/2025(1)		S		622	D	$1.46	98,018	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:

1. Represents the number of shares sold to cover the tax withholding obligations in connection with the vesting of certain restricted stock units and does not represent a discretionary sale by the Reporting Person.

Remarks:

	/s/ Christian Mulvihill	09/17/2025
	** 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

What did Greenidge (GREEL) insider Christian Mulvihill report on Form 4?

He reported two sales of Class A common stock on 09/16/2025 to cover tax withholding related to vested restricted stock units.

How many shares did the reporting person own after the reported transactions?

Beneficial ownership reported as 98,640 shares and 98,018 shares on the respective reporting lines following the transactions.

At what prices were the shares sold in the Form 4?

Sales were reported at $1.47 and $1.46 per share.

Why were the shares sold according to the filing?

The filing states the shares were sold to cover tax withholding obligations from RSU vesting and were not discretionary sales.

When was the Form 4 signed?

The Form 4 was signed by Christian Mulvihill on 09/17/2025.