Bitcoin’s hashrate crossed 1 zettahash per second earlier in 2026, a figure that would have seemed fictional as recently as 2022. The network is processing more proof-of-work than at any point in its history, and mining hardware efficiency has improved enough that some operators are running profitable rigs at electricity costs that would have bankrupted them two halving cycles ago. That’s the good news.
The harder question is what happens in April 2028, when the block subsidy drops from 3.125 BTC to 1.5625 BTC.
The 2024 Halving Was Unusually Forgiving
The April 2024 halving played out against a backdrop that softened the revenue shock for miners: price had already climbed significantly heading into the event, institutional ETF demand was absorbing supply, and transaction fees spiked during the Runes protocol launch in the days surrounding the halving block. That fee spike was a one-off, but it gave miners a temporary buffer that the 2028 halving may not replicate.
Miner revenue is a function of block subsidy plus fees. If fees stay structurally low - which they have been for much of 2025 and 2026 outside of periodic inscription activity - then each halving places more pressure on the fee side of the equation to compensate. So far, fees have not stepped up to fill that role in any sustained way.
Efficiency Gains Have a Floor
Chip manufacturers have pushed ASIC efficiency dramatically over the past four years. The latest generation of miners from major hardware producers operates well below 20 joules per terahash. But silicon efficiency improvements follow a curve that gets harder to steepen at the margins - the gains from 15 J/TH to 10 J/TH are harder to achieve than from 25 J/TH to 20 J/TH. Miners cannot hardware-upgrade their way through every halving indefinitely.
This matters because the miners most exposed in 2028 will likely be those still operating second-generation machines in high-cost energy environments. Large-scale operations with long-term power purchase agreements at sub-3 cent rates will survive; others face a margin compression that a hashrate adjustment can only partially fix.
What Fees Would Need to Do
For the 2028 halving to be as painless as 2024, either Bitcoin’s price would need to approximately double the pre-halving level, or average transaction fees would need to rise substantially and stay there. Neither is guaranteed. Layer 2 activity, while growing, routes economic throughput off the base layer - which is good for scaling but does not directly generate L1 fee revenue.
The mempool dynamic that pushed fees up during Ordinals and Runes mania was real but unpredictable. Relying on that pattern to recur on schedule in April 2028 is not a mining business strategy.
The hashrate record is worth acknowledging. What miners do with the next 18 months of preparation - balance sheet management, energy contract positioning, hardware refresh cycles - will determine whether that record becomes a ceiling or a floor.