Alyeska Group holds 1.4M ESS Tech shares, 5.15% stake (GWH)

Rhea-AI Filing Summary

ESS Tech, Inc. Schedule 13G/A amendment shows Alyeska Investment Group, L.P. (with related Alyeska entities) beneficially owns 1,400,000 shares of Common Stock, representing 5.15% of the class as of March 31, 2026. The filing cites 27,173,757 shares outstanding per the Form 10-K dated March 5, 2026. The disclosure is a joint filing; Anand Parekh is named but disclaims beneficial ownership. The statement notes Alyeska Investment Group, L.P. exercises voting and investment control over shares held by Alyeska Master Fund, L.P.

Insights

Institutional Ownership Analyst

Alyeska holds a 5.15% stake in ESS Tech as of March 31, 2026.

Alyeska Investment Group, L.P. and affiliated entities report beneficial ownership of 1,400,000 shares, with voting and dispositive power reported as shared. The filing cites the company’s outstanding share count of 27,173,757 from the Form 10-K dated March 5, 2026.

The disclosure is a passive beneficial-ownership report under Schedule 13G/A and indicates position size only; subsequent trading or strategy details are not included in the excerpt.

Corporate Governance Specialist

Joint filing and disclaimer language clarify attribution and control.

The statement is filed on behalf of Alyeska Investment Group, L.P., Alyeska Fund GP, LLC, and Anand Parekh under Rule 13d-1(k). It records that the investment manager exercises voting and investment control over the shares held by Alyeska Master Fund, L.P.

The filing includes a formal disclaimer by Mr. Parekh regarding beneficial ownership; the document is a standard disclosure of an institutional holder, not an operational or transaction notice.

Key Figures

Beneficial ownership: 1,400,000 shares Ownership percent: 5.15% Shares outstanding: 27,173,757 shares

3 metrics

Beneficial ownership 1,400,000 shares Amount beneficially owned as of March 31, 2026

Ownership percent 5.15% Percent of class based on cited outstanding shares

Shares outstanding 27,173,757 shares Shares outstanding per Form 10-K dated March 5, 2026

Key Terms

Schedule 13G/A, Beneficially own, Shared dispositive power

3 terms

Schedule 13G/A regulatory

"Item 1. Name of issuer: ESS Tech, Inc.; form type indicated at top of excerpt"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

Beneficially own financial

"Exhibit Information As of March 31, 2026, the Reporting Persons beneficially own 1,400,000 shares"

Beneficially own means having the economic rights and risks of a security—such as the right to receive dividends, sell the shares, or profit from price changes—whether or not your name appears on the official share register. Think of it like renting a car: you use it and reap the benefits even if the title lists someone else. Investors care because beneficial ownership determines who truly controls value, must be disclosed under securities rules, and can signal potential influence or trading activity that affects a stock’s price.

Shared dispositive power regulatory

"Shared Dispositive Power 1,400,000.00 appears in the ownership table"

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)

03/31/2026

(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

Alyeska Investment Group, L.P.

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 0.00
6	Shared Voting Power 1,400,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,400,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,400,000.00

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)

5.15 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

CUSIP Number(s): 26916J205

1

Names of Reporting Persons

Alyeska Fund GP, 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 0.00
6	Shared Voting Power 1,400,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,400,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,400,000.00

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)

5.15 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP Number(s): 26916J205

1

Names of Reporting Persons

Anand Parekh

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 0.00
6	Shared Voting Power 1,400,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,400,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,400,000.00

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)

5.15 %

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) Alyeska Investment Group, L.P. (ii) Alyeska Fund GP, LLC (iii) Anand Parekh
(b)	Address or principal business office or, if none, residence: (i) 77 West Wacker Drive, 7th Floor, Chicago, IL 60601 (ii) 77 West Wacker Drive, 7th Floor, Chicago, IL 60601 (iii) 77 West Wacker Drive, 7th Floor, Chicago, IL 60601
(c)	Citizenship: (i) Alyeska Investment Group, L.P. - Delaware (ii) Alyeska Fund GP, LLC - Delaware (iii) Anand Parekh - United States of America
(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: 1,400,000
(b)	Percent of class: 5.15%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 0
	(ii) Shared power to vote or to direct the vote: 1,400,000
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 1,400,000
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.

Alyeska Investment Group, L.P.

Signature:	Jason Bragg
Name/Title:	Jason Bragg | Chief Financial Officer
Date:	05/15/2026

Alyeska Fund GP, LLC

Signature:	Jason Bragg
Name/Title:	Jason Bragg | Chief Financial Officer
Date:	05/15/2026

Anand Parekh

Signature:	Anand Parekh
Name/Title:	Anand Parekh | Self
Date:	05/15/2026

Exhibit Information

As of March 31, 2026, the Reporting Persons beneficially own 1,400,000 shares of Common Stock. The number of shares of Common Stock outstanding (27,173,757) is based on the Form 10-K dated March 5, 2026. Position held by Alyeska Master Fund, L.P. Alyeska Investment Group, L.P., as investment manager, exercises voting and investment control over the shares held by Alyeska Master Fund, L.P. Anand Parekh, as Chief Executive Officer of Alyeska Investment Group, L.P., may be deemed the beneficial owner of such shares. Mr. Parekh disclaims beneficial ownership of such shares. JOINT FILING STATEMENT PURSUANT TO RULE 13d-1(k) The undersigned acknowledge and agree that the foregoing statement on SCHEDULE 13G, is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on SCHEDULE 13G, shall be filed on behalf of each of the undersigned without the necessity of filing additional joint acquisition statements. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained therein, but shall not be responsible for the completeness and accuracy of the information concerning the others, except to the extent that he or it knows or has reason to believe that such information is inaccurate.

FAQ

What stake does Alyeska report in ESS Tech (GWH)?

Alyeska reports beneficial ownership of 1,400,000 shares, equal to 5.15% of Common Stock as of March 31, 2026. The shares outstanding cited are 27,173,757 per the Form 10-K dated March 5, 2026.

Which Alyeska entities are named in the Schedule 13G/A for ESS Tech?

The filing names Alyeska Investment Group, L.P., Alyeska Fund GP, LLC, and Anand Parekh. The investment manager is reported to exercise voting and investment control over shares held by Alyeska Master Fund, L.P.

Does Anand Parekh claim beneficial ownership of the reported shares?

The filing lists Anand Parekh among the reporting persons but states that Mr. Parekh disclaims beneficial ownership of the shares while noting his role as Chief Executive Officer of Alyeska Investment Group, L.P.

What is the basis for the cited shares outstanding figure?

The filing cites 27,173,757 shares outstanding based on the Form 10-K dated March 5, 2026. That outstanding count is presented as the reference used to calculate the 5.15% ownership percentage.