Material Agreement, Financial Obligation, Private Placement (Form 8-K)

Indenture and Notes

On September 30, 2025, Cipher Mining Inc. (the "Company") issued $1,300,000,000 aggregate principal amount of its 0.00% Convertible Senior Notes due 2031 (the "Notes"). The Notes were issued pursuant to, and are governed by, an indenture (the "Indenture"), dated as of September 30, 2025, between the Company and U.S. Bank Trust Company, National Association, as trustee (the "Trustee"). Pursuant to the purchase agreement between the Company and the representative of the initial purchasers of the Notes, the Company granted the initial purchasers a 13-dayoption to purchase up to an additional $200,000,000 aggregate principal amount of Notes. The Notes issued on September 30, 2025 include the full exercise of such option by the initial purchasers.

The Notes will be the Company's senior, unsecured obligations and will be (i) equal in right of payment with the Company's existing and future senior, unsecured indebtedness, including the Company's existing $172,500,000 principal amount of convertible notes due in 2030; (ii) senior in right of payment to the Company's existing and future indebtedness that is expressly subordinated to the Notes; (iii) effectively subordinated to the Company's existing and future secured indebtedness, to the extent of the value of the collateral securing that indebtedness; and (iv) structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, and (to the extent the Company is not a holder thereof) preferred equity, if any, of the Company's subsidiaries.

The Notes will not bear regular interest, and the principal amount of the Notes will not accrete. The Notes will mature on October 1, 2031, unless earlier repurchased, redeemed or converted. Prior to July 1, 2031, the Notes will be convertible only upon satisfaction of certain conditions and during certain period, and thereafter, the Notes will be convertible at any time until the close of business on the second scheduled trading day immediately preceding the maturity date. The Company will settle conversions by paying or delivering, as applicable, cash, shares of its common stock, or a combination of cash and shares of its common stock, at the Company's election. The Company's ability to elect to settle conversions in whole or in part in shares of common stock will, subject to a limited exception, be subject to receipt of stockholder approval for an increase in the number of its authorized shares of common stock or the Company otherwise increasing the number of shares of its common stock available to settle conversions of the Notes. The initial conversion rate is 62.3733 shares of the Company's common stock per $1,000 principal amount of Notes, which represents an initial conversion price of approximately $16.03 per share of the Company's common stock. The conversion rate and conversion price will be subject to customary adjustments upon the occurrence of certain events. In addition, if certain corporate events that constitute a "Make-Whole Fundamental Change" (as defined in the Indenture) occur, then the conversion rate will, in certain circumstances, be increased for a specified period of time.

The Notes will be redeemable, in whole or in part (subject to certain limitations described below), for cash at the Company's option at any time, and from time to time, on or after October 5, 2028 and on or before the 30th scheduled trading day immediately before the maturity date, but only if (i) the last reported sale price per share of the Company's common stock exceeds 130% of the conversion price on (1) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends the related redemption notice and (2) the trading day immediately before the date the Company sends such redemption notice, and (ii) certain "liquidity conditions" (as defined in the Indenture) having been satisfied. However, the Company may not redeem less than all of the outstanding Notes unless at least $100.0 million aggregate principal amount of Notes are outstanding and not called for redemption as of the time the Company sends the related redemption notice. The redemption price will be a cash amount equal to the principal amount of the Notes to be redeemed, plus accrued and unpaid special interest and additional interest, if any, to, but excluding, the redemption date. In addition, calling any Note for redemption will constitute a Make-Whole Fundamental Change with respect to that Note, in which case the conversion rate applicable to the conversion of that Note will be increased in certain circumstances if it is converted after it is called for redemption.

If certain corporate events that constitute a "Fundamental Change" (as defined in the Indenture) occur, then, subject to a limited exception for certain cash mergers, noteholders may require the Company to repurchase their Notes at a cash repurchase price equal to the principal amount of the Notes to be repurchased, plus accrued and unpaid special interest and additional interest, if any, to, but excluding, the "Fundamental Change Repurchase Date" (as defined in the Indenture). The definition of Fundamental Change includes certain business combination transactions involving the Company, certain de-listingevents with respect to the Company's common stock and the approval of a liquidation or dissolution plan by the Company's stockholders.

Unless prior to October 1, 2029 the Company has issued a notice of redemption in respect of all then-outstanding Notes, each noteholder will have the right to require the Company to repurchase such noteholder's Notes on October 1, 2029 for cash in an amount equal to the principal amount of the Notes to be repurchased plus accrued and unpaid special interest and additional interest, if any, to, but not excluding, the "Optional Repurchase Date" (as defined in the Indenture).

The Notes will have customary provisions relating to the occurrence of "Events of Default" (as defined in the Indenture), which include the following: (i) certain payment defaults on the Notes (which, in the case of a default in the payment of interest on the Notes, will be subject to a 30-daycure period); (ii) the Company's failure to send certain notices under the Indenture within specified periods of time; (iii) the Company's failure to convert a Note upon the exercise of a conversion right; (iv) the Company's failure to comply with certain covenants in the Indenture relating to the Company's ability to consolidate with or merge with or into, or sell, lease or otherwise transfer, in one transaction or a series of transactions, all or substantially all of the assets of the Company and its subsidiaries, taken as a whole, to another person; (v) a default by the Company in its other obligations or agreements under the Indenture or the Notes if such default is not cured or waived within 60 days after notice is given in accordance with the Indenture; (vi) certain defaults by the Company or any of its significant subsidiaries with respect to indebtedness for borrowed money of at least $80,000,000; (vii) one or more final judgments in excess of $80,000,000 rendered against the Company or any of its significant subsidiaries, which remain undischarged or unstayed for 60 days after the date on which the right to appeal has expired or on which all rights to appeal have been extinguished; and (viii) certain events of bankruptcy, insolvency and reorganization involving the Company or any of its significant subsidiaries.

If an Event of Default involving bankruptcy, insolvency or reorganization events with respect to the Company (and not solely with respect to a significant subsidiary of the Company) occurs, then the principal amount of, and all accrued and unpaid special interest and additional interest, if any, on, all of the Notes then outstanding will immediately become due and payable without any further action or notice by any person. If any other Event of Default occurs and is continuing, then, the Trustee, by notice to the Company, or noteholders of at least 25% of the aggregate principal amount of Notes then outstanding, by notice to the Company and the Trustee, may declare the principal amount of, and all accrued and unpaid special interest and additional interest, if any, on, all of the Notes then outstanding to become due and payable immediately. However, notwithstanding the foregoing, the Company may elect, at its option, that the sole remedy for an Event of Default relating to certain failures by the Company to comply with certain reporting covenants in the Indenture consists exclusively of the right of the noteholders to receive special interest on the Notes for up to 365 days at a specified rate per annum not exceeding 0.50% on the principal amount of the Notes.

The above description of the Indenture and the Notes is a summary and is not complete. A copy of the Indenture and the form of the certificate representing the Notes are filed as Exhibits 4.1 and 4.2, respectively, to this Current Report on Form 8-K,and the above summary is qualified by reference to the terms of the Indenture and the Notes set forth in such Exhibits.

Capped Call Transactions

On September 25, 2025, in connection with the pricing of the offering of Notes, the Company entered into privately negotiated capped call transactions (the "Base Capped Call Transactions") with certain of the initial purchasers or their affiliates and certain other financial institutions (the "Option Counterparties"). In addition, on September 26, 2025, in connection with the initial purchasers' exercise of their option to purchase additional Notes, the Company entered into additional capped call transactions (the "Additional Capped Call Transactions," and, together with the Base Capped Call Transactions, the "Capped Call Transactions") with each of the Option Counterparties. The Capped Call Transactions cover, subject to customary anti-dilutionadjustments, the number of shares of the Company's common stock that initially underlie the Notes. The Capped Call Transactions are generally expected to reduce the potential dilution to the Company's common stock upon any conversion of the Notes and/or offset any potential cash payments the Company is required to make in excess of the principal amount of converted Notes, as the case may be with such reduction and/or offset subject to a cap. The cap price of the Capped Call Transactions is initially $23.32, which represents a premium of 100% over the last reported sale price of the Company's common stock on September 25, 2025. The cost of the Capped Call Transactions was approximately $82.7 million.

The Capped Call Transactions are separate transactions, each between the Company and the applicable Option Counterparty, and are not part of the terms of the Notes and will not affect any holder's rights under the Notes or the Indenture. Holders of the Notes will not have any rights with respect to the Capped Call Transactions.

The above description of the Capped Call Transactions is a summary and is not complete. A copy of the form of confirmation for the Capped Call Transactions is filed as Exhibit 10.1 to this Current Report on Form 8-K,and the above summary is qualified by reference to the terms of the confirmations set forth in such Exhibit.

The disclosure set forth in Item 1.01 above is incorporated by reference into this Item 2.03.

The disclosure set forth in Item 1.01 above is incorporated by reference into this Item 3.02. The Notes were issued to the initial purchasers in reliance upon Section 4(a)(2) of the Securities Act of 1933, as amended (the "Securities Act"), in transactions not involving any public offering. The Notes were resold by the initial purchasers to persons whom the initial purchasers reasonably believe are "qualified institutional buyers," as defined in, and in accordance with, Rule 144A under the Securities Act. Any shares of the Company's common stock that may be issued upon conversion of the Notes will be issued in reliance upon Section 3(a)(9) of the Securities Act as involving an exchange by the Company exclusively with its security holders.