Bitcoin’s hashrate crossed 1 zettahash per second earlier this year, a milestone that would have seemed absurd to anyone watching the network in 2020. More compute is pointed at Bitcoin than at any point in its history. The network is, by this measure, the most secure it has ever been.
That achievement is quietly strangling a significant portion of the mining industry.
The Post-Halving Squeeze
The April 2024 halving cut the block subsidy from 6.25 BTC to 3.125 BTC. Miners absorbed that shock partly because Bitcoin’s price ran hard through late 2024 and into 2025. But hashrate has continued climbing through 2025 and into 2026, meaning more machines are competing for a smaller subsidy. Mining difficulty adjusts upward to match, and the math gets worse for anyone running older-generation ASICs.
Antminer S19-era machines - which powered much of the network through 2022 and 2023 - are increasingly uneconomical outside of regions with sub-$0.03/kWh electricity. Large publicly traded miners like Marathon Digital and Riot Platforms have been steadily rotating to newer hardware, but smaller operations don’t have that capital flexibility.
The result is ongoing consolidation. Bitcoin mining is becoming an industrial-scale business faster than most of the “decentralization” arguments from the early 2020s anticipated.
Fee Revenue Is Still Unreliable
The long-run security model for Bitcoin depends on transaction fees replacing the block subsidy as it declines toward zero across future halvings. That transition is nowhere near on track. Transaction fee revenue remains highly episodic - spiking during periods of Ordinals or Runes activity, then collapsing back to negligible levels during quiet stretches.
For miners, this makes revenue forecasting nearly impossible beyond a few weeks out. Operating costs - electricity contracts, debt service on hardware financing - don’t flex the same way.
Who Survives
The miners best positioned going forward share a few characteristics: long-term power purchase agreements at low fixed rates, balance sheets that can absorb hardware refresh cycles, and geographic diversification across jurisdictions. Vertical integration into AI compute - which several large miners have pursued - provides some revenue cushion but is a different business with different risk.
Small-scale mining as a viable hobby or side income is effectively over in most high-cost electricity markets. That’s not a moral judgment, just where the numbers have landed.