Glenbrook Capital Management filed Amendment No. 3 to its Schedule 13D with the SEC on October 30, 2026, disclosing updated beneficial ownership and a previously undisclosed minority interest in a newly engaged strategic advisor to SenesTech, Inc.

Key Highlights

  • Beneficial ownership: Glenbrook Capital Management reported beneficial ownership of 2,196,973 shares of SenesTech common stock, representing 40.51% of the class.
  • Shared voting and dispositive power: The filing reports 0 shares held with sole voting or dispositive power, and 2,196,973 shares held with shared voting and shared dispositive power.
  • Total acquisition cost: Approximately $4.43 million (excluding brokerage commissions) was paid to acquire shares during the reporting period.
  • Sandstrom connection disclosed: Glenbrook holds a minority ownership interest in Sandstrom Partners, Inc., which SenesTech announced on October 28, 2026 it had engaged as a strategic advisor on marketing and branding.
  • Strategic study commissioned: In April 2026, Glenbrook commissioned, at its expense, a strategic study of the rodent control market by Sandstrom Partners, Inc., the results of which were presented to SenesTech's Board.
  • Share count basis: The percentage reported is based on 5,423,542 shares of common stock outstanding as of August 4, 2026, as reported in SenesTech's quarterly report for the period ended June 30, 2026.

Glenbrook's Ownership Position and Disclosed Relationships at SenesTech

According to the filing, Glenbrook Capital Management, a Nevada-organized entity, reported aggregate beneficial ownership of 2,196,973 shares of SenesTech, Inc. (NASDAQ:SNES) common stock, par value $0.001 per share, representing 40.51% of the class. The source of funds is listed as "AF," indicating funds derived from the general working capital of the Glenbrook Funds and Accounts. The filing states that a total of approximately $4.43 million, excluding brokerage commissions, was paid to acquire shares during the period in which the reporting person has been subject to reporting obligations under Section 13(d) or 13(g) of the Exchange Act.

Amendment No. 3 also updates Item 4, disclosing that in April 2026, Glenbrook commissioned a strategic study of the rodent control market from Sandstrom Partners, Inc. at Glenbrook's expense, and that the results were presented to SenesTech's Board. The filing further discloses that on October 28, 2026, SenesTech announced the engagement of Sandstrom as a strategic advisor on marketing and branding. Glenbrook states that it "holds a minority ownership interest in Sandstrom." SenesTech, according to its principal executive office address listed in the filing, is headquartered in Surprise, Arizona, and operates in the rodent control market.

All transactions in SenesTech common stock effected by Glenbrook since the filing of Amendment No. 2 were conducted in the open market, according to the filing, and are detailed in Schedule A attached as Exhibit 99.1. The filing was signed by Robert W. Lishman, Director of Glenbrook Capital Management, on October 30, 2026.

What Was Disclosed

Glenbrook Capital Management disclosed amended beneficial ownership of 2,196,973 SenesTech shares (40.51%), an approximately $4.43 million total acquisition cost, and a minority ownership interest in Sandstrom Partners, Inc., a firm SenesTech recently engaged as a strategic advisor.