Amendments to Bylaws (Form 8-K)

Item 5.03. Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

On December 23, 2025, Grayscale Investments Sponsors, LLC (the "Sponsor") amended the fiscal year-end of Grayscale Horizen Trust (ZEN) (the "Trust") for financial accounting purposes, moving from September 30 to December 31 of each year, effective for the fiscal year beginning on January 1, 2025 and ending on December 31, 2025. The Trust intends to file a transition report on Form 10-KT with the Securities and Exchange Commission for the transition period beginning October 1, 2025 and ending December 31, 2025.

The relevant amendments are set forth in Amendment No. 4 to the Amended and Restated Declaration of Trust and Trust Agreement ("Trust Agreement"), a copy of which is attached hereto as Exhibit 4.1 and incorporated herein by reference.

Item 8.01. Other Events.

As previously disclosed in the Trust's Current Report on Form 8-K filed on July 18, 2025, the Sponsor indicated that it intended to evaluate, following the completion of the migration of all ZEN tokens from the legacy Horizen blockchain to the Base Network (the "Migration"), among other factors, the adoption and usage of such tokens and the ongoing viability of the Trust following the Migration, and that the Sponsor expected to make a determination as to the foregoing by December 2025.

Furthermore, the Sponsor discusses the security status of ZEN and the Sponsor's transactions in ZEN with external counsel, and has received a memorandum regarding the status of ZEN and the Sponsor's transactions in ZEN under the federal securities laws from external counsel. While the Sponsor does not currently believe that the Migration alters its prior conclusions regarding
the status of ZEN under the federal securities laws, the Migration could impact the Sponsor and its external counsel's analysis, which the Sponsor is continuing to evaluate as part of the ongoing viability of the Trust. See "Part I-Item 1A. Risk Factors-A determination that ZEN or any other digital asset is a "security" may adversely affect the value of ZEN and the value of the Shares, and result in potentially extraordinary, nonrecurring expenses to, or termination of, the Trust" in the Trust's Annual Report on Form 10-K for the fiscal year ended September 30, 2025, as amended from time to time (the "Annual Report").

As of the date hereof, the Sponsor has determined that it will continue the affairs of the Trust and does not intend, at this time, to discontinue or dissolve the Trust pursuant to the Trust Agreement based on the matters evaluated. However, the Sponsor may re-evaluate the Trust's viability in the future in accordance with the Trust Agreement and applicable law.

Capitalized terms used but not defined herein have the meanings ascribed to such terms in the Trust's Annual Report.