[8-K] ESS Tech, Inc. Reports Material Event

Rhea-AI Filing Summary

ESS Tech, Inc. (NYSE: GWH) filed an 8-K disclosing the immediate, non-severance termination of Chief Financial Officer Anthony Rabb on 1-Aug-2025. The company states the dismissal is not related to accounting policies, reporting practices, or internal controls. Controller Kate Suhadolnik (age 36) is elevated to interim CFO, becoming principal financial and accounting officer effective the same date. Suhadolnik joined ESS in Sept-2021, became Controller in Apr-2023, and previously spent nine years at Deloitte & Touche. Her annual salary is $220,000 with discretionary cash/stock bonus; employment remains at-will. The board has started an internal/external search for a permanent CFO. No related-party transactions, family ties, or special arrangements were reported, and she has executed the standard indemnification agreement previously filed as Ex. 10.12.

The filing contains no new financial results or guidance. Investors should monitor potential impacts on capital-raising plans and execution risk while the CFO position is interim.

Positive

• Internal succession limits disruption by promoting Controller Kate Suhadolnik, who already knows ESS Tech’s systems and controls.
• No accounting or internal-control issues were cited, reducing the risk of restatements or regulatory scrutiny.

Negative

• Sudden CFO termination without severance can signal disagreement or performance issues, creating leadership instability.
• Interim status and Suhadolnik’s limited public-company CFO experience may concern investors during capital-intensive growth phase.

Insights

Sell-side Equity Analyst

TL;DR: Sudden CFO exit is mildly negative; no accounting red flags soften the blow.

The abrupt, no-severance dismissal of CFO Rabb introduces short-term uncertainty, particularly as ESS Tech is still pre-profit and may require additional capital for long-duration battery build-outs. Management assures the market the issue is non-financial, averting Sarbanes-Oxley anxiety. Elevating an experienced internal Controller limits transition friction, yet Suhadolnik lacks public-company C-suite history. A permanent hire timeline is unspecified, which could weigh on investor confidence and debt negotiations. Net impact: modestly negative but not thesis-breaking.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): August 1, 2025

ESS TECH, INC.

(Exact name of registrant as specified in charter)

Delaware

001-39525

98-1550150

(State or other jurisdiction of incorporation)

(Commission File Number)

(I.R.S. Employer Identification Number)

26440 SW Parkway Ave., Bldg. 83 Wilsonville, Oregon						97070
(Address of principal executive offices)						(Zip code)

(855) 423-9920

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, $0.0001 par value per share

GWH

The New York Stock Exchange

Warrants, each fifteen warrants exercisable for one share of common stock at an exercise price of $172.50

GWH.W

The New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

Termination of Chief Financial Officer

On August 1, 2025, Anthony Rabb, Chief Financial Officer of ESS Tech, Inc. (the “Company”), was terminated from the Company without severance effective as of August 1, 2025. The termination is not related to any issues regarding accounting policies, standards or practices, reporting obligations or other regulations, or internal control over financial reporting.

Appointment of Interim Chief Financial Officer

The Board of Directors of the Company is conducting a search of potential internal and external candidates to replace Mr. Rabb. Kate Suhadolnik, 36, the Company’s current Controller, has been appointed as the interim Chief Financial Officer and has assumed the duties as principal financial officer and principal accounting officer of the Company, effective August 1, 2025. Ms. Suhadolnik has been with the Company since September 2021 and served as the Company’s Controller since April 2023. Ms. Suhadolnik has 14 years of experience in the financial and accounting sector. Immediately prior to joining the Company, Ms. Suhadolnik was the Corporate Accounting & Reporting Manager at The Standard, an insurance and financial services company, from July 2020 to September 2021. Ms. Suhadolnik also held various positions of increasing responsibility at Deloitte & Touche LLP from September 2011 to June 2020. Ms. Suhadolnik received her bachelor’s degree in accounting and business administration from Gonzaga University and is a Certified Public Accountant.

Ms. Suhadolnik’s annualized salary is currently $220,000 and she is currently eligible to receive an annual cash and stock performance bonus. Ms. Suhadolnik’s salary and bonus may be adjusted at the discretion of the Compensation Committee of the Board. Ms. Suhadolnik’s employment is on an “at will basis.”

There are no arrangements or understandings between Ms. Suhadolnik and any other person pursuant to which she was appointed principal financial officer and principal accounting officer. Ms. Suhadolnik does not have any family relationships with any director or executive officer of the Company, or person nominated or chosen by the Company to become a director or executive officer, and she has no direct or indirect material interest in any transaction required to be disclosed pursuant to Item 404(a) of Regulation S-K.

The Company entered into an indemnification agreement with Ms. Suhadolnik, in the form filed by the Company as exhibit 10.12 to the Company’s Current Report on Form 8-K filed on October 15, 2021.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.

Dated: August 1, 2025

ESS TECH, INC.
By:			/s/ Kelly F. Goodman
Name:			Kelly F. Goodman
Title:			Interim Chief Executive Officer

FAQ

Why was ESS Tech (GWH) CFO Anthony Rabb terminated?

The 8-K states Rabb was terminated on 1-Aug-2025 without severance; the dismissal was not related to accounting or reporting issues.

Who is the interim CFO at ESS Tech after the termination?

Controller Kate Suhadolnik was appointed interim CFO, principal financial officer and principal accounting officer effective 1-Aug-2025.

Does the ESS Tech filing mention accounting irregularities?

No. The company explicitly notes the termination was not connected to accounting policies, standards, or internal controls.

What is Kate Suhadolnik’s compensation as interim CFO?

Her annualized salary remains $220,000 with eligibility for discretionary cash and stock bonuses.

Is ESS Tech searching for a permanent CFO?

Yes. The board has begun evaluating both internal and external candidates to permanently fill the CFO role.