ESS Tech, Inc. (GWH) sees 8.14% ownership disclosed by Ayrton Capital and Alto Fund

Rhea-AI Filing Summary

ESS Tech, Inc. received an updated ownership report showing that Ayrton Capital LLC, Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B, and Waqas Khatri collectively report beneficial ownership of 2,563,934 shares of common stock as of June 30, 2026. This consists of 463,934 shares of common stock and 2,100,000 shares issuable upon exercise of warrants, which are subject to a 9.99% beneficial ownership blocker. Based on 29,389,170 shares outstanding as of May 4, 2026 plus the warrant shares, the filing reports an 8.14% stake for each Reporting Person, with sole voting and sole dispositive power over these shares and no shared voting or dispositive power.

Key Figures

Beneficially owned shares: 2,563,934 shares Current common shares held: 463,934 shares Warrant shares issuable: 2,100,000 shares +3 more

6 metrics

Beneficially owned shares 2,563,934 shares Total ESS Tech common stock beneficially owned by each Reporting Person as of June 30, 2026

Current common shares held 463,934 shares ESS Tech common stock held by the Reporting Persons, excluding warrant shares

Warrant shares issuable 2,100,000 shares ESS Tech common stock issuable upon exercise of Warrants held by the Reporting Persons

Ownership percentage 8.14% Percentage of ESS Tech common stock beneficially owned by each Reporting Person

Shares outstanding baseline 29,389,170 shares ESS Tech common shares outstanding as of May 4, 2026, used for ownership calculation

Beneficial ownership blocker 9.99% Limit on warrant exercises to keep beneficial ownership below this level

Key Terms

beneficial ownership blocker, Sole Voting Power, dispositive power, Schedule 13G, +1 more

5 terms

beneficial ownership blocker regulatory

"The issuable shares of Common Stock related to the exercise of the Warrants are subject to a 9.99% beneficial ownership blocker."

A beneficial ownership blocker is a legal or structural device that prevents a shareholder from being treated as the ultimate owner of enough shares to trigger control, reporting, or voting thresholds. Think of it like a speed bump that stops an investor from reaching a stake size that would force corporate disclosure or change control rights. Investors care because it affects who controls the company, how shares vote, regulatory filings, takeover risk and therefore potential value or liquidity of their holdings.

Sole Voting Power regulatory

"5 | Sole Voting Power 2,563,934.00"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

dispositive power regulatory

"Sole Dispositive Power 2,563,934.00"

Dispositive power is the authority to decide the final outcome of an asset, legal claim, contract, or corporate action — in effect the power to dispose of or resolve something. For investors it matters because whoever holds that authority can determine who gets paid, who controls an asset or vote, and how risks and returns are allocated; think of it like holding the key that lets you lock in the winner or loser in a deal.

Schedule 13G regulatory

"The percentages below are based on ... as reported in this Schedule 13G/A."

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

warrants financial

"2,100,000 shares of Common Stock issuable on the exercise of certain warrants (the "Warrants") held by the Reporting Persons."

Warrants are special documents that give you the right to buy a company's stock at a set price before a certain date. They are often used as a way for companies to attract investors or raise money, and their value can increase if the company's stock price goes up.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/13/2026 - 12:53 PM Accepted by SEC EDGAR 08/13/2026 - 12:53 PM Learn about SEC filing dates

FAQ

What ownership stake in ESS Tech, Inc. (GWH) is reported in this Schedule 13G/A?

The filing reports that the Reporting Persons beneficially own 2,563,934 ESS Tech, Inc. shares, representing 8.14% of the common stock. This percentage is based on 29,389,170 shares outstanding plus 2,100,000 warrant shares.

Who are the Reporting Persons in the ESS Tech, Inc. (GWH) Schedule 13G/A?

The Reporting Persons are Ayrton Capital LLC, Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B, and Waqas Khatri. Ayrton Capital is the investment manager to the Fund, and Khatri serves as managing member of Ayrton and as a director of the Fund.

How many ESS Tech (GWH) shares are held versus issuable under warrants?

The position consists of 463,934 ESS Tech common shares currently held and 2,100,000 additional shares issuable upon exercise of warrants. Together these total the reported 2,563,934 beneficially owned shares.

What is the 9.99% beneficial ownership blocker mentioned for ESS Tech (GWH)?

The filing states that the 2,100,000 warrant shares are subject to a 9.99% beneficial ownership blocker. This provision limits warrant exercises to avoid the Reporting Persons’ beneficial ownership exceeding 9.99% of ESS Tech’s outstanding common stock.

As of what dates are the ESS Tech (GWH) ownership figures and share count calculated?

Beneficial holdings are reported as of June 30, 2026. The 8.14% ownership is calculated using 29,389,170 shares outstanding as of May 4, 2026, plus 2,100,000 shares issuable upon exercise of the warrants.

Do the Reporting Persons share voting or dispositive power over ESS Tech (GWH) shares?

The filing reports sole voting power and sole dispositive power over 2,563,934 shares for each Reporting Person, and zero shared voting or shared dispositive power. All reported authority is non-shared.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

ESS Tech, Inc.

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

26916J205

(CUSIP Number)

06/30/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 26916J205

1

Names of Reporting Persons

Ayrton Capital LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 2,563,934.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 2,563,934.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,563,934.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

8.14 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

CUSIP Number(s): 26916J205

1

Names of Reporting Persons

Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 2,563,934.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 2,563,934.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,563,934.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

8.14 %

12

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13G

CUSIP Number(s): 26916J205

1

Names of Reporting Persons

Waqas Khatri

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 2,563,934.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 2,563,934.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,563,934.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

8.14 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: ESS Tech, Inc.
(b)	Address of issuer's principal executive offices: 26440 SW Parkway Ave., Bldg. 83, Wilsonville, OR, 97070
Item 2.
(a)	Name of person filing: (i) Ayrton Capital LLC; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B; and (iii) Waqas Khatri
(b)	Address or principal business office or, if none, residence: (i) Ayrton Capital LLC, 55 Post Rd West, 2nd Floor Westport, CT 06880; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B, Suite #7 Grand Pavilion Commercial Centre, 802 West Bay Road, Grand Cayman, P.O. Box 10250, Cayman Islands; and (iii) Waqas Khatri 55 Post Rd West, 2nd Floor Westport, CT 06880
(c)	Citizenship: (i) Ayrton Capital LLC: United States; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: Cayman Islands; and (iii) Waqas Khatri: United States
(d)	Title of class of securities: Common Stock, $0.0001 par value per share
(e)	CUSIP No.: 26916J205
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: Ayrton Capital LLC: 2,563,934; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 2,563,934; and (iii) Waqas Khatri: 2,563,934. Represents (i) 463,934 shares of Common Stock held by the Reporting Persons; (ii) 2,100,000 shares of Common Stock issuable on the exercise of certain warrants (the "Warrants") held by the Reporting Persons. The issuable shares of Common Stock related to the exercise of the Warrants are subject to a 9.99% beneficial ownership blocker. The shares reported herein represent Common Stock of ESS Tech, Inc. (the "Issuer") held by Alto Opportunity Master Fund, SPC- Segregated Master Portfolio B, a Cayman Islands exempted company (the "Fund"). The Fund is a private investment vehicle for which Ayrton Capital LLC, a Delaware limited liability company (the "Investment Manager"), serves as the investment manager. Waqas Khatri serves as the managing member of the Investment Manager (all of the foregoing, collectively, the "Reporting Persons").
(b)	Percent of class: The percentages below are based on (i) 29,389,170 shares of Common Stock of the Issuer that were outstanding as of May 4, 2026; and (ii) 2,100,000 shares of Common Stock issuable on the exercise of the Warrants held by the Reporting Persons. The amount of shares outstanding was based upon a statement in the Issuer's 10-Q filed on May 7, 2026. For the sake of clarity, the holdings of the Reporting Persons reported herein are as of June 30, 2026. (i) Ayrton Capital LLC: 8.14%; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 8.14%; and (iii) Waqas Khatri: 8.14%.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: (i) Ayrton Capital LLC: 2,563,934; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 2,563,934; and (iii) Waqas Khatri: 2,563,934
	(ii) Shared power to vote or to direct the vote: (i) Ayrton Capital LLC: 0; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 0; and (iii) Waqas Khatri: 0
	(iii) Sole power to dispose or to direct the disposition of: (i) Ayrton Capital LLC: 2,563,934; Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 2,563,934; Waqas Khatri: 2,563,934
	(iv) Shared power to dispose or to direct the disposition of: (i) Ayrton Capital LLC: 0; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 0; (iii) Waqas Khatri: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Ayrton Capital LLC

Signature:	/s/ Waqas Khatri
Name/Title:	Waqas Khatri / Managing Member
Date:	08/13/2026

Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B

Signature:	/s/ Waqas Khatri
Name/Title:	Waqas Khatri / Director
Date:	08/13/2026

Waqas Khatri

Signature:	/s/ Waqas Khatri
Name/Title:	Waqas Khatri
Date:	08/13/2026