UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

     Date of Report (Date of earliest event reported): September 25, 2025

    

Grayscale Bitcoin Mini Trust ETF

(Exact name of Registrant as Specified in Its Charter)


Delaware	001-42194	99-6383052
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)

c/o Grayscale Investments Sponsors, LLC 290 Harbor Drive, 4th Floor
Stamford, Connecticut		06902
(Address of Principal Executive Offices)		(Zip Code)

     Registrant’s Telephone Number, Including Area Code: 212 668-1427

    

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:


	☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
	☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
	☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
	☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:


Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Grayscale Bitcoin Mini Trust ETF Shares	BTC	NYSE Arca, Inc.

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01 Entry into a Material Definitive Agreement.

On September 25, 2025, Grayscale Investments Sponsors, LLC, the sponsor (the “Sponsor”) of Grayscale Bitcoin Mini Trust ETF (the “Trust”), and Anchorage Digital Bank N.A. (“Anchorage Digital”), a national trust bank chartered by the Office of the Comptroller of the Currency, entered into a certain Second Amendment to Master Custody Service Agreement (the “Second Amendment”), which provides that the Trust is added as a party to a certain Master Custody Service Agreement, dated as of August 8, 2025 (and together with the Second Amendment, the “Anchorage Digital Custodian Agreement” or the “Agreement”).

Pursuant to the Anchorage Digital Custodian Agreement, Anchorage Digital will provide services related to custody and safekeeping of the Trust’s Bitcoin holdings.

The Sponsor expects to utilize Anchorage Digital’s services to custody a portion of the Trust’s Bitcoin. The Trust’s existing custody arrangement with Coinbase Trust Company, LLC (“Coinbase”) is unaffected by the Trust’s entry into the Agreement, and Coinbase remains the Trust’s primary custodian. The Sponsor shall, in its sole discretion, determine the amounts held at either custodian as permitted by the Trust Agreement. At the current time, the Sponsor has not determined the amount of the Trust’s Bitcoin it will move to Anchorage Digital. The addition of Anchorage Digital reflects the Sponsor’s ongoing risk management approach as part of the Trust’s growing size. References to “the Custodian” in our annual report on Form 10-K for the fiscal period ended December 31, 2024 will be deemed to refer to Coinbase, Anchorage Digital and/or other Custodians, collectively or in their individual capacities, as the context may require.

Under the Anchorage Digital Custodian Agreement, Anchorage Digital is required to keep all of the private keys associated with the Trust’s Bitcoin held at Anchorage Digital in cold storage. Cold storage is a safeguarding method by which the private key(s) corresponding to Bitcoin is (are) generated and stored in an offline manner. Private keys are generated in offline computers or devices that are not connected to the internet so that they are more resistant to being hacked. By contrast, in hot storage, the private keys are held online, where they are more accessible, leading to more efficient transfers, though they are potentially more vulnerable to being hacked.

In the event of a fork of the Bitcoin blockchain, the Anchorage Digital Custodian Agreement provides that Anchorage Digital may temporarily suspend services, and may, in its sole discretion, determine whether or not to support (or cease supporting) either branch of the forked protocol entirely, provided that Anchorage shall use commercially reasonable efforts to avoid ceasing to support both branches of such forked protocol.

The Anchorage Digital Custodian Agreement requires the Trust to indemnify Anchorage Digital, its affiliates, and their respective officers, directors, agents, employees and representatives against certain losses arising from or related to the Trust’s material breach of the Anchorage Digital Custodian Agreement, among other things, except where a claim was caused by certain acts of Anchorage Digital. The Anchorage Digital Custodian Agreement also requires Anchorage Digital to maintain insurance policies and coverage.

The foregoing description of the Anchorage Digital Custodian Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Anchorage Digital Custodian Agreement filed with this Current Report on Form 8-K as Exhibit 10.1 and Exhibit 10.2.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits



Exhibit No.		Description

10.1		Master Custody Service Agreement, dated August 8, 2025, between the Trust and Anchorage Digital Bank N.A.
10.2		Second Amendment to Master Custody Service Agreement, dated September 25, 2025, between the Trust and Anchorage Digital Bank N.A.
104		Cover Page Interactive Data File (the cover page XBRL tags are embedded within the inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.


			Grayscale Investments Sponsors, LLC, as Sponsor of Grayscale Bitcoin Mini Trust ETF

Date:	September 26, 2025	By:	/s/ Edward McGee
			Name: Edward McGee Title: Chief Financial Officer*

* The Registrant is a trust and the identified person signing this report is signing in their capacity as an authorized officer of Grayscale Investments Sponsors, LLC, the Sponsor of the Registrant.

Grayscale Bitcoin Mini Trust ETF 8-K