[Form 3] ESS Tech, Inc. Initial Statement of Beneficial Ownership

Rhea-AI Filing Summary

Kate Eileen Suhadolnik, identified as Interim CFO and an officer of ESS Tech, Inc. (ticker GWH), reported beneficial ownership of 30,186 shares of common stock in an initial Form 3 filing for the event dated 08/01/2025. Of these shares, 23,805 are restricted stock units (RSUs) granted prior to Section 16 reporting obligations and the filing details multiple RSU grants with staggered vesting schedules beginning August 20, 2025. The form was signed via power of attorney on 08/28/2025.

Positive

• Insider ownership disclosed: 30,186 common shares beneficially owned, supporting transparency
• Detailed RSU schedules: Multiple RSU grants with explicit vesting dates beginning August 20, 2025

Negative

• None.

Insights

Financial Analyst

TL;DR: Routine Section 16 disclosure showing modest insider holdings and scheduled RSU vesting.

The filing is an initial Form 3 for an officer, documenting beneficial ownership of 30,186 common shares composed largely of RSUs with specified grant dates and vesting schedules. This is a standard compliance disclosure required when an insider becomes subject to Section 16. The ownership level disclosed is transparent but not, on its face, material to valuation absent other context.

Corporate Governance Expert

TL;DR: Compliance-focused filing; details on deferred compensation vesting are clear and timely.

The submission clearly itemizes prior RSU awards and future vesting tranches, which aids transparency around executive compensation timing. The use of a power of attorney for signature is noted. There are no indications of option holdings or derivative positions in this Form 3.

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

Suhadolnik Kate Eileen

(Last) (First) (Middle)

C/O ESS TECH, INC.

26440 SW PARKWAY AVE., BLDG. 83

(Street)

WILSONVILLE OR 97070

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
08/01/2025

3. Issuer Name and Ticker or Trading Symbol
ESS Tech, Inc. [ GWH ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Interim CFO

5. 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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	30,186	D(1)(2)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Of the reported shares, 23,805 are represented by restricted stock units, or RSUs, awarded prior to the date on which the reporting person became subject to Section 16. An award representing 394 RSUs was awarded on December 23, 2021. The remaining 48 RSUs vest in two equal quarterly installments beginning on August 20, 2025. An award representing 184 RSUs was awarded on February 8, 2022. The remaining 33 RSUs vest in three equal quarterly installments beginning on August 20, 2025. An award representing 821 RSUs was awarded on November 2, 2022. The remaining 128 RSUs vest in two equal quarterly installments beginning on August 20, 2025.

2. An award representing 5,351 RSUs was awarded on March 13, 2023. The remaining 2,338 RSUs vest in seven equal quarterly installments beginning on August 20, 2025. An award representing 5,867 RSUs was awarded on February 15, 2024. The remaining 4,032 RSUs vest in eleven equal quarterly installments beginning on August 20, 2025. An award representing 18,375 RSUs was awarded on April 13, 2025. The remaining 17,226 RSUs vest in fifteen equal quarterly installments beginning on August 20, 2025.

Remarks:

Exhibit 24.1 Power of Attorney

	/s/ Bianca Boschmans, by power of attorney	08/28/2025
	** 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 5 (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 the Form 3 for ESS Tech (GWH) report?

The Form 3 reports that Interim CFO Kate Eileen Suhadolnik beneficially owns 30,186 shares of common stock, mostly RSUs.

When is the event date and when was the Form 3 signed?

The event requiring the statement is dated 08/01/2025 and the form was signed by power of attorney on 08/28/2025.

How many RSUs are included and when do they vest?

The filing lists 23,805 RSUs granted prior to Section 16 status and additional RSU awards with remaining portions vesting in scheduled quarterly installments beginning August 20, 2025.

Does the Form 3 report any derivative securities or options?

No. Table II for derivative securities shows no entries; only non-derivative common stock and RSUs are reported.

What is the reporting person’s role at ESS Tech?

The reporting person is identified as an Officer with the title Interim CFO and is a Section 16 reporting person.