[Form 4] Greenidge Generation Holdings Inc. 8.50% Senior Notes due 2026 Insider Trading Activity

Rhea-AI Filing Summary

Christian Mulvihill, Chief Financial Officer of Greenidge Generation Holdings Inc., reported a non-discretionary sale of Class A common stock on 08/13/2025 to satisfy tax withholding on vested restricted stock units. The filing shows 615 shares were sold at $1.36 per share, and the reporting person continues to beneficially own 98,645 shares in a direct ownership form after the transaction.

The Form 4 clarifies this was not a discretionary sale but a withholding sale tied to RSU vesting, and it was filed by a single reporting person who is an officer (CFO) of the issuer.

Insights

Corporate Governance Expert

TL;DR: Reported sale was a standard, non-discretionary withholding of 615 shares for RSU taxes; governance implications are minimal.

The Form 4 discloses a withholding sale executed on 08/13/2025 of 615 Class A shares at $1.36 per share to cover tax obligations arising from vested restricted stock units. The reporting person remains a direct holder of 98,645 shares after the transaction. This disclosure adheres to Section 16 reporting requirements and demonstrates compliance and transparency. The transaction is administrative in nature and does not indicate voluntary monetization or a change in control of the insider’s economic exposure.

Securities Analyst

TL;DR: Small, non-discretionary insider sale; quantitatively immaterial to holdings and unlikely to affect investor valuation.

The sale of 615 shares represents a minor change relative to the remaining direct holding of 98,645 shares reported after the transaction. The per-share price reported is $1.36. Because the filing explicitly states the sale was to satisfy tax withholding on RSUs and not a discretionary sale, the market-significance is limited. Reporting timing and single-person filing are consistent with routine compensation-related reporting.

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

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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)
08/13/2025

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	08/13/2025(1)		S		615	D	$1.36	98,645	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	08/13/2025
	** 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).
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