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): November 4, 2025

CIPHER MINING INC.

(Exact name of registrant as specified in its charter)

1 Vanderbilt Avenue

Floor 54

New York, New York 10017

(Address of principal executive offices) (Zip Code)

(332) 262-2300

(Registrant’s telephone number, including area code)

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 (see General Instruction A.2. below):

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

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 7.01. Regulation FD Disclosure.

As previously disclosed by Cipher Mining Inc. (“Cipher” or the “Company”) on September 25, 2025, Cipher Barber Lake LLC, the Company’s wholly-owned indirect subsidiary, entered into a lease with Fluidstack USA II Inc. (“Fluidstack”) and other agreements relating to the development and lease of a 244 MW HPC data center facility near Colorado City, Texas (the “Barber Lake Facility”). Attached hereto as Exhibit 99.1 to this Current Report on Form 8-K is certain illustrative financial information concerning the Barber Lake Facility.

The information contained in Item 7.01 of this Current Report (as well as in Exhibit 99.1 attached hereto) is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities and Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and such information shall not be deemed to be incorporated by reference into any of the Company’s filings under the Securities Act of 1933, as amended or the Exchange Act.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

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 hereunto duly authorized.