Were ESS Tech CFO’s share sales part of open-market transactions?

Yes. Both transactions are coded as open-market or private sales of common stock, with weighted average prices reported. The company’s disclosure emphasizes that the purpose was to satisfy tax withholding on vested restricted stock units rather than to liquidate a large ownership stake.

ESS Tech (GWH) CFO logs small stock sales tied to RSU tax withholding

Filing Impact

(Neutral)

Filing Sentiment

(Neutral)

Form Type

Rhea-AI Filing Summary

ESS Tech, Inc. Chief Financial Officer Kate Eileen Suhadolnik reported small open-market sales of company stock primarily to cover tax obligations. On two days, she sold a total of 3,657 shares of ESS Tech common stock at weighted average prices around $0.92–$0.93 per share.

The footnotes state these shares were sold to cover tax withholding obligations tied to the vesting of restricted stock units. After these transactions, she still directly holds 160,757 shares of ESS Tech common stock, indicating she maintains a substantial equity position in the company.

Insider Trade Summary

Net Seller: 3,657 shares ($3,389)

Net Sell 2 txns

Insider Suhadolnik Kate Eileen

Role Chief Financial Officer

Sold 3,657 shs ($3K)

Type	Security	Shares	Price	Value
Sale	Common Stock	1,922	$0.9346	$2K
Sale	Common Stock	1,735	$0.9181	$2K

Holdings After Transaction: Common Stock — 160,757 shares (Direct, null)

Footnotes (1)

These shares were sold to cover tax withholding obligations in connection with the vesting of restricted stock units ("RSUs"). The price reported in sold Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.9024 to $0.971, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price. A portion of these securities are RSUs. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The price reported in sold Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.92 to $0.95, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

Key Figures

Shares sold 2026-05-22: 1,922 shares Shares sold 2026-05-21: 1,735 shares Total shares sold: 3,657 shares +3 more

6 metrics

Shares sold 2026-05-22 1,922 shares Open-market sale of common stock at $0.9346 per share

Shares sold 2026-05-21 1,735 shares Open-market sale of common stock at $0.9181 per share

Total shares sold 3,657 shares Combined open-market sales related to RSU tax withholding

Holding after 2026-05-22 160,757 shares Direct ownership of ESS Tech common stock after reported sales

Weighted average price 2026-05-22 $0.9346/share Average sale price for 1,922 shares of common stock

Weighted average price 2026-05-21 $0.9181/share Average sale price for 1,735 shares of common stock

Key Terms

restricted stock units, weighted average price, open-market sale, tax withholding obligations

4 terms

restricted stock units financial

"These shares were sold to cover tax withholding obligations in connection with the vesting of restricted stock units ("RSUs")."

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

weighted average price financial

"The price reported in sold Column 4 is a weighted average price."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

open-market sale financial

"transaction_action: open-market sale"

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

tax withholding obligations financial

"These shares were sold to cover tax withholding obligations in connection with the vesting of restricted stock units ("RSUs")."

Form 4 Insider Transactions: What Each Field Means →

05/26/2026 - 06:59 PM

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^*

Suhadolnik Kate Eileen

(Last)

(First)

(Middle)

C/O ESS TECH, INC.

26440 SW PARKWAY AVE., BLDG. 83

(Street)

WILSONVILLE

OREGON

97070

(City)

(State)

(Zip)

UNITED STATES

(Country)

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/21/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	05/21/2026		S		1,735⁽¹⁾	D	$0.9181⁽²⁾	162,679⁽³⁾	D
Common Stock	05/22/2026		S		1,922⁽¹⁾	D	$0.9346⁽⁴⁾	160,757⁽³⁾	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. These shares were sold to cover tax withholding obligations in connection with the vesting of restricted stock units ("RSUs").

2. The price reported in sold Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.9024 to $0.971, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

3. A portion of these securities are RSUs. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock.

4. The price reported in sold Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.92 to $0.95, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

	/s/ Kate Suhadolnik	05/26/2026
	** 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.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR

FAQ

What insider transactions did ESS Tech (GWH) report for CFO Kate Suhadolnik?

ESS Tech reported that CFO Kate Eileen Suhadolnik sold 3,657 shares of common stock in two open-market transactions. These sales were disclosed as related to tax withholding on vesting restricted stock units and are part of her routine equity compensation activity.

How many ESS Tech (GWH) shares did the CFO sell and at what prices?

CFO Kate Suhadolnik sold 3,657 ESS Tech common shares in total. She sold 1,922 shares at a weighted average price of about $0.9346 and 1,735 shares at about $0.9181, with footnotes noting execution across price ranges on each trading day.

Why did ESS Tech’s CFO sell shares according to the Form 4 filing?

The filing states the shares were sold to cover tax withholding obligations arising from the vesting of restricted stock units. This means the transactions are tied to equity compensation and related taxes, rather than discretionary portfolio rebalancing or a change in her long-term ownership stance.

How many ESS Tech (GWH) shares does the CFO still hold after these sales?

After the reported transactions, CFO Kate Suhadolnik directly holds 160,757 shares of ESS Tech common stock. This post-transaction balance suggests the reported sales represent only a portion of her total position, with significant equity exposure remaining aligned with shareholders.