The former bitcoin miner extended its Barber Lake data center lease to 20 years with a follow-on commitment from an unnamed AI lab, while pushing delivery into early 2027. Its shares fell with the miner group.
Cipher Digital's latest lease amendment doubles the length of its biggest AI contract. The fine print shifts some cost risk onto the company.
The company, formerly known as Cipher Mining, disclosed in a securities filing on Friday that it had amended its lease with Fluidstack for the Barber Lake high-performance computing facility. It also signed a binding commitment with an unnamed "leading AI lab" for a 10-year follow-on lease that extends the total contracted term to 20 years. The additions bring about $5.2 billion of contracted revenue.
The schedule and the costs
The filing also resets the delivery timeline. Data halls will now be delivered between the fourth quarter of 2026 and the first quarter of 2027, with first rent in the fourth quarter of 2026.
Cipher will bear the first $359.3 million of construction costs above the initial budget. Above that amount, the tenant will reimburse 50% of overruns over the 20-year term, paid as additional rent at a contracted return. The filing does not disclose the size of the original budget, so the share of total cost that $359.3 million represents cannot be calculated from the filing.
The market reaction
Cipher shares traded near $17.66 on Friday afternoon, down about 2.4%. That was in line with other publicly traded bitcoin miners, which fell between 2% and 5% on the day. MARA Holdings, IREN, CleanSpark and Core Scientific were all lower. The filing did not lift the stock away from its group.
That reaction invites two readings. One is that investors had already priced the Barber Lake project and see the extension as incremental. The other is that the first-loss cost overrun and the phased delivery are drawing as much attention as the headline revenue.
The shift from mining
Cipher is one of several bitcoin miners converting power and sites to host AI computing, where long-term leases offer steadier revenue than mining rewards. A 20-year contract gives it a revenue base that bitcoin prices do not determine. It also makes execution risk, on construction costs and delivery dates, the main variable.
The first rent payments in the fourth quarter will show whether the revised schedule holds. Any disclosure of the original budget, or of costs running toward the $359.3 million threshold, would tell investors how much of the overrun protection the company is likely to use.