SenesTech (SNES) investor Glenbrook discloses 19.95% ownership stake

Rhea-AI Filing Summary

Glenbrook Capital Management, a Nevada-based investment manager, reports beneficial ownership of 1,057,804 shares of SenesTech common stock, representing 19.95% of the 5,303,426 shares outstanding as of May 11, 2026.

Glenbrook acquired the position for approximately $3.6 million from its working capital through funds and managed accounts, viewing SenesTech as undervalued and an attractive investment. It also holds warrants in PFS Trust and an employee profit-sharing plan that are subject to 9.99% and 4.99% beneficial ownership blockers, limiting further exercises.

The firm characterizes the holding as an investment but has been, and may continue to be, actively engaged with SenesTech’s management, board and other shareholders on strategy, operations, marketing, capital structure and governance, and may increase or decrease its economic exposure over time.

Filing Explained

The filing states that none of the warrants held by GCM EPSP are exercisable at this time because their 4.99% beneficial-ownership blocker prevents exercise above that threshold.

Key Figures

Beneficial ownership: 1,057,804 shares Ownership percentage: 19.95 % Shares outstanding: 5,303,426 shares +4 more

7 metrics

Beneficial ownership 1,057,804 shares Shares of SenesTech common stock beneficially owned by Glenbrook Capital Management

Ownership percentage 19.95 % Portion of SenesTech common stock beneficially owned based on 5,303,426 shares outstanding as of May 11, 2026

Shares outstanding 5,303,426 shares SenesTech common stock outstanding as of May 11, 2026

Investment cost approximately $3.6 million Total consideration paid by Glenbrook Capital Management to acquire the reported SenesTech securities

Beneficial ownership blocker 9.99 % Maximum ownership allowed after exercising PFS Trust’s Series I Common Stock Warrant

Beneficial ownership blocker 4.99 % Maximum ownership allowed after exercising GCM Employee Profit-Sharing Plan warrant; currently blocks exercise

Event date 07/22/2026 Date of event triggering Glenbrook Capital Management’s Schedule 13D reporting obligation

Key Terms

beneficial owner, margin accounts, Series I Common Stock Warrant, beneficial ownership blocker, +1 more

5 terms

beneficial owner regulatory

"for the purposes of Section 13 of the Securities Exchange Act of 1934, the beneficial owner"

A beneficial owner is the person who ultimately owns or controls a financial asset or property, even if their name isn't directly on official documents. Think of it like someone who secretly holds the keys to a safe deposit box—others may appear to have access, but the true owner is the one who benefits from what's inside. Identifying beneficial owners helps ensure transparency and prevent illegal activities like money laundering or fraud.

margin accounts financial

"Positions in the shares of Common Stock may be held in margin accounts."

A margin account is a brokerage account that lets an investor borrow money from the broker to buy more securities than they could with cash alone, using the securities in the account as security for the loan. Think of it like a mortgage for stock purchases: borrowing increases potential gains but also magnifies losses, can trigger a forced sale if the account falls below required limits, and carries interest costs—factors investors must manage carefully.

Series I Common Stock Warrant financial

"PFS Trust holds a Series I Common Stock Warrant of the Issuer (the "Warrants")"

beneficial ownership blocker regulatory

"which contains a 9.99% beneficial ownership blocker (the "9.99% 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.

investment manager financial

"The principal business of GCM is serving as investment manager to the Glenbrook Funds"

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

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Available on EDGAR 07/23/2026 - 07:30 PM Accepted by SEC EDGAR 07/23/2026 - 07:30 PM Learn about SEC filing dates

FAQ

What percentage of SenesTech (SNES) does Glenbrook Capital Management report owning?

Glenbrook Capital Management reports beneficial ownership of 19.95% of SenesTech’s common stock. This reflects 1,057,804 shares based on 5,303,426 shares outstanding as of May 11, 2026, as stated in SenesTech’s most recent quarterly report.

How many SenesTech (SNES) shares does Glenbrook Capital Management beneficially own?

Glenbrook Capital Management beneficially owns 1,057,804 shares of SenesTech common stock. The ownership is held through various Glenbrook funds and managed accounts, giving the firm shared voting and dispositive power over these shares, equal to 19.95% of the outstanding stock.

How much did Glenbrook Capital Management pay for its SenesTech (SNES) investment?

Glenbrook Capital Management paid approximately $3.6 million to acquire its SenesTech securities. The funds came from Glenbrook’s general working capital, and some positions may be held in margin accounts alongside other securities, according to the disclosed ownership information.

What is Glenbrook Capital Management’s stated purpose for its SenesTech (SNES) stake?

Glenbrook views SenesTech’s securities as undervalued and an attractive investment and holds them for investment purposes. It is reviewing the position on a continuing basis and has engaged, and may continue to engage, with management, the board and other shareholders on business and governance matters.

What warrant restrictions apply to Glenbrook Capital Management’s SenesTech (SNES) position?

Glenbrook-related entities hold SenesTech warrants with 9.99% and 4.99% beneficial ownership blockers. These provisions prevent exercising warrants if doing so would push aggregate beneficial ownership above those thresholds, and currently render the warrants held by GCM’s employee profit-sharing plan non-exercisable.

Can Glenbrook Capital Management change its SenesTech (SNES) ownership level?

Glenbrook may increase or decrease its SenesTech exposure over time. It may buy or sell common stock or related instruments in open-market or private transactions and may enter into derivatives that adjust its economic exposure, while reserving the right to change its intentions.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

SenesTech, Inc.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

81720R604

(CUSIP Number)

Glenbrook Capital Management
5396 Avenue 18 1/2,
Chowchilla, CA, 93160
650-441-9525

Ele Klein & Danny Goldstein
McDermott Will & Schulte LLP, 919 Third Avenue
New York, NY, 10022
212-756-2446

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

07/22/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

schemaVersion:

SCHEDULE 13D

CUSIP Number(s): 81720R604

1

Name of reporting person

GLENBROOK CAPITAL MANAGEMENT

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NEVADA

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 1,057,804.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 1,057,804.00

11

Aggregate amount beneficially owned by each reporting person

1,057,804.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

19.95 %

14

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, par value $0.001 per share
(b)	Name of Issuer: SenesTech, Inc.
(c)	Address of Issuer's Principal Executive Offices: 777 W. PINNACLE PEAK ROAD, SUITE B104, PHOENIX, ARIZONA , 85027.
Item 2.	Identity and Background
(a)	This statement is filed by Glenbrook Capital Management, a Nevada corporation ("GCM" or the "Reporting Person") with respect to the shares of common stock, par value $0.001 per share (the "Common Stock") of SenesTech, Inc., a Delaware corporation (the "Issuer"). Grover T. Wickersham ("Mr. Wickersham") is the Chairman and CEO of GCM as well as a member of its board of directors, which is also comprised of two additional directors, namely Lindsay Wickersham and Robert W. Lishman (collectively and together with GCM and Mr. Wickersham, the "Covered Persons"). GCM serves as the investment manager to certain funds and managed accounts (the "Glenbrook Funds and Accounts"), including PFS Trust ("PFS Trust") and Glenbrook Capital Management Inc. Employee Profit-Sharing Plan ("GCM EPSP"), which hold the shares of Common Stock and Warrants reported herein. The filing of this statement should not be construed as an admission that any of the foregoing persons or any Reporting Person is, for the purposes of Section 13 of the Securities Exchange Act of 1934, the beneficial owner of the securities reported herein.
(b)	The principal business address of each of the Covered Persons is 5396 Avenue 18 1/2, Chowchilla, CA 93610
(c)	The principal business of GCM is serving as investment manager to the Glenbrook Funds and Accounts. The principal business of Mr. Wickersham is serving as Chairman and CEO of GCM. The principal businesses of each of Lindsay Wickersham and Robert W. Lishman is serving as a private investor.
(d)	None of the Covered Persons have, during the last five years, been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).
(e)	None of the Covered Persons have, during the past five years, been party to a civil proceeding of a judicial or administrative body of competent jurisdiction and, as a result of such proceedings, were or are subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or violation with respect to such laws.
(f)	GCM is a Nevada corporation. Each of Mr. Wickersham and Lindsay Wickersham is a citizen of both the United States and United Kingdom. Robert W. Lishman is a United States citizen.
Item 3.	Source and Amount of Funds or Other Consideration
	Funds for the purchase of the securities reported herein were derived from the general working capital of Glenbrook Capital Management. A total of approximately $3.6 million was paid to acquire such securities. Positions in the shares of Common Stock may be held in margin accounts. Because other securities may be held in such margin accounts, it may not be possible to determine the amounts, if any, of margin used to purchase the shares of Common Stock.
Item 4.	Purpose of Transaction
	The Reporting Person originally acquired the securities reported herein because it believes the securities are undervalued and represent an attractive investment opportunity and they continue to hold the shares of Common Stock reported herein for investment purposes. The Reporting Person previously reported its beneficial ownership on Schedule 13G pursuant to Rule 13d-1(c) under the Act. The Reporting Person also intends to review its investment in the Issuer on a continuing basis. The Reporting Person has and may continue to engage in discussions with management, the board of directors (the "Board"), other stockholders of the Issuer, and other persons regarding the Issuer, including with respect to its business, operations, marketing and overall business strategy, capital structure, and governance, though the Reporting Person may change its intentions with respect to any and all of the foregoing. The Reporting Person may also take steps to explore and prepare for various plans and actions, and propose transactions, before forming an intention to engage in such plans or actions or proceed with such transactions. The Reporting Person intends to make introductions to certain persons and businesses that the Reporting Person believes may be able to assist the Issuer with respect to certain operational and/or financial matters. In this regard, the Reporting Person has advanced certain funds to marketing or branding advisors to provide strategic advice regarding certain of the Issuer's products. The Reporting Person intends to review its investment in the Issuer on a continuing basis and depending upon various factors, including without limitation, the Issuer's financial position and strategic direction, the outcome of any discussions referenced above, overall market conditions, other investment opportunities available to the Reporting Person, and the availability of securities of the Issuer at prices that would make the purchase or sale of such securities desirable, the Reporting Person may endeavor (i) to increase or decrease its position in the Issuer through, among other things, the purchase or sale of securities of the Issuer, including through transactions involving shares of Common Stock and/or other equity, debt, notes, other securities, or derivative or other instruments that are based upon or relate to the value of securities of the Issuer in the open market or in private transactions, on such terms and at such times as the Reporting Person may deem advisable and/or (ii) to enter into transactions that increase or decrease its economic exposure to the shares of Common Stock without affecting its beneficial ownership of the shares of Common Stock or adjust its exposure to the shares of Common Stock in ways that would affect its beneficial ownership of the shares of Common Stock. Except as set forth in this Item 4, the Reporting Person does not currently have any plans or proposals that relate to or would result in any of the actions specified in clauses (a) through (j) of Item 4 of Schedule 13D. The Reporting Person reserves the right to formulate plans or proposals, and to take such actions with respect to its investment in the Issuer, including any or all of the actions set forth in clauses (a) through (j) of Item 4, and to change its intentions, at any time, as it deems appropriate.
Item 5.	Interest in Securities of the Issuer
(a)	See rows (11) and (13) of the cover page to this Schedule 13D for the aggregate number of shares of Common Stock and percentages of shares of Common Stock beneficially owned by the Reporting Person. The aggregate percentage of shares of Common Stock reported to be beneficially owned by the Reporting Person is based upon 5,303,426 shares of Common Stock outstanding as of May 11, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2026, filed with the Securities and Exchange Commission (the "SEC") on May 13, 2026.
(b)	See rows (7) through (10) of the cover page to this Schedule 13D for the number of shares of Common Stock as to which the Reporting Person has the sole or shared power to vote or direct the vote and sole or shared power to dispose or to direct the disposition.
(c)	All transactions in the shares of Common Stock effected by the Reporting Person during the past sixty (60) days, which were all in the open market, are set forth in Schedule A, and are incorporated herein by reference.
(d)	No person other than the Reporting Person is known to have the right to receive, or the power to direct the receipt of dividends from, or proceeds from the sale of, the shares of Common Stock held by the Glenbrook Funds and Accounts.
(e)	Not applicable.
Item 6.	Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer
	PFS Trust holds a Series I Common Stock Warrant of the Issuer (the "Warrants"), which contains a 9.99% beneficial ownership blocker (the "9.99% Blocker"), pursuant to which PFS Trust cannot exercise such Warrant to the extent the Reporting Person, PFS Trust or any of its or their affiliates, would beneficially own, after any such exercise, more than 9.99% of the outstanding Common Stock. In addition, GCM EPSP holds a Warrant which contains a 4.99% beneficial ownership blocker (the "4.99% Blocker"), pursuant to which GCM EPSP cannot exercise such Warrant to the extent the Reporting Person, GCM EPSP or any of its or their affiliates, would beneficially own, after any such exercise, more than 4.99% of the outstanding Common Stock. Consequently, due to the 4.99% Blocker, none of the Warrants held by GCM EPSP are exercisable at this time. Except as set forth herein, there are no contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 hereof and between such persons and any person with respect to any securities of the Issuer, including any class of the Issuer's securities used as a reference security, in connection with any of the following: call options, put options, security-based swaps or any other derivative securities, transfer or voting of any of the securities, finder's fees, joint ventures, loan or option arrangements, guarantees of profits, division of profits or loss, or the giving or withholding of proxies.
Item 7.	Material to be Filed as Exhibits.
	None.

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.

GLENBROOK CAPITAL MANAGEMENT

Signature:	/s/ Robert W. Lishman
Name/Title:	Director
Date:	07/23/2026