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

Rhea-AI Filing Summary

Greenidge Generation Holdings (GREE): Form 4 insider transaction. Chief Financial Officer Christian Mulvihill reported a sale of 609 shares of Class A common stock on 10/13/2025 at $2.07 per share. The filing states the sale was made to cover tax withholding obligations tied to the vesting of restricted stock units and was not a discretionary sale. Following the transaction, Mulvihill beneficially owns 97,409 shares.

Insights

Insider transactions analyst

Routine tax-withholding sale; neutral signal.

The CFO sold 609 shares at $2.07 on 10/13/2025 specifically to satisfy tax withholding from RSU vesting. Such transactions are mechanical and typically do not reflect a view on valuation.

Post-transaction holdings are 97,409 shares, indicating continued equity exposure. The filing characterizes the sale as non-discretionary, which reduces interpretive risk around insider sentiment.

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^*

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)
10/13/2025

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	10/13/2025(1)		S		609	D	$2.07	97,409	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	10/15/2025
	** 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 GREE's CFO report on Form 4?

A sale of 609 shares of Class A common stock on 10/13/2025 at $2.07 per share.

Why were the shares sold by GREE's CFO?

To cover tax withholding obligations from the vesting of certain restricted stock units; it was not a discretionary sale.

How many GREE shares does the CFO hold after the transaction?

Beneficial ownership is 97,409 shares following the reported transaction.

Who is the reporting person on the Form 4 for GREE?

The reporting person is Christian Mulvihill, Chief Financial Officer.

What type of security was involved in the GREE Form 4?

Class A common stock of Greenidge Generation Holdings Inc. (GREE).

Was the transaction part of a trading plan?

The filing includes a checkbox for Rule 10b5-1(c); the sale was disclosed as for tax withholding related to RSU vesting.