"Bitcoin Mining After the 4th Halving — How Proof-of-Work Economics Are Shifting"

# Bitcoin Mining After the 4th Halving — How Proof-of-Work Economics Are Shifting

The fourth Bitcoin halving occurred on April 19, 2024, at block height 840,000. The block subsidy dropped from 6.25 BTC to 3.125 BTC per block. For Bitcoin mining companies, this was the moment every financial model had been building toward — and the moment when the industry's structural weaknesses became impossible to paper over. The halving is a pre-programmed reduction in miner revenue. The question is always whether price appreciation will compensate, and whether the miners who were marginally profitable before the halving survive the margin compression that follows.

The fourth halving played out against a more complex macro backdrop than its predecessors. The Bitcoin ETF approvals in January 2024 brought significant institutional capital into the market, and Bitcoin's price had already rallied substantially in anticipation. But price appreciation and hashrate both reached historic levels, meaning that miner competition remained fierce even as the subsidy was cut. Understanding what has happened in the year-plus since the halving requires looking at the economics from multiple angles.

## Revenue Math After the Halving

The fundamental economics of Bitcoin mining are straightforward: miners receive block subsidies plus transaction fees in exchange for the electricity and capital deployed to hash. After the halving, the subsidy component of revenue was cut in half. For miners running older, less efficient hardware — particularly anything older than the Antminer S19 generation — the revenue per terahash dropped below the break-even electricity cost at the prices that prevailed in the months following the halving.

The transaction fee revenue component added meaningful complexity. The launch of Runes — a new protocol for creating fungible tokens on Bitcoin, introduced at the halving block itself — drove a brief but significant spike in transaction fees. In the weeks following the halving, fee revenue temporarily exceeded subsidy revenue, a phenomenon last seen during the 2017 Segwit activation debate. The spike did not last; Runes fee activity moderated substantially as the novelty faded. But it demonstrated a point that Bitcoin proponents have long emphasized and skeptics have long questioned: transaction fee revenue can, under conditions of high on-chain activity, materially compensate for declining subsidies.

The broader pattern, however, is one of margin compression for smaller and less efficient operators. The all-in sustaining cost per bitcoin — incorporating electricity, hardware depreciation, hosting fees, and overhead — rose sharply for the median miner in the months following the halving. The largest industrial miners, operating at scale with renewable power purchase agreements at below-market rates, could sustain profitability at lower bitcoin prices. Smaller miners, particularly those in high-electricity-cost jurisdictions, could not.

## Hash Rate Trends and Network Security

The Bitcoin network's total hash rate continued to climb through 2025, reaching sustained levels above 700 exahashes per second (EH/s) — more than double the hash rate at the third halving in 2020. This trajectory appears paradoxical: if miner revenue per terahash is declining, why does total hash rate keep increasing?

The answer lies in the hardware technology curve and geographic arbitrage. The Antminer S21 Pro and comparable machines from MicroBT generate roughly 216 terahashes per second at 16 joules per terahash — significantly more efficient than the S19 generation that dominated the previous halving cycle. Miners who upgraded to the latest generation hardware saw their economics improve even as older operators struggled. Meanwhile, the geographic dispersion of mining has continued: the 2021 Chinese mining ban drove operations to North America, Kazakhstan, Russia, and increasingly to the Middle East and Nordic countries, each with different electricity cost structures.

The network's security — measured by the cost to mount a 51% attack — has never been higher in absolute terms. Whether this level of security is "necessary" given Bitcoin's current use case and value store properties is a separate philosophical question. From a pure economic security standpoint, the network is more resistant to attack than at any previous point in its history.

## The Renewable Energy Shift

One of the more consequential long-term trends in Bitcoin mining is the shift toward renewable energy sources. The Bitcoin Mining Council, an industry group that voluntarily tracks energy mix among its members, has reported sustainable energy mixes above 50% for several years. The motivations are partly environmental (ESG compliance for publicly listed miners), partly economic (renewable energy, particularly stranded or curtailed renewable energy, can be extremely cheap), and partly strategic (grid flexibility contracts with utilities offer miners premium rates to reduce consumption during peak demand).

Several large miners have signed contracts with nuclear power operators, attracted by the combination of extremely low marginal electricity costs and zero-carbon credentials. In Texas, where deregulated electricity markets and abundant wind and solar resources make for a complex but potentially lucrative grid relationship, miners have become significant participants in demand response programs — curtailing operations during grid stress events in exchange for capacity payments. This grid-balancing function has given Bitcoin mining a new kind of economic relationship with the broader energy system.

## Industrial Consolidation

The fourth halving has accelerated the consolidation trend that has characterized every previous halving cycle. Mining is a scale business: the largest operators benefit from lower hardware costs (bulk purchasing discounts), lower electricity costs (large-scale power purchase agreements), lower capital costs (access to public equity and debt markets), and operational expertise that spreads over larger hash rate bases.

The public Bitcoin mining sector — companies like Marathon Digital Holdings, CleanSpark, Riot Platforms, and Core Scientific — has expanded hash rate aggressively through equity issuances and debt financing, even as marginal profitability has declined. Their strategy is straightforward: capture market share now, survive through the low-price periods, and benefit disproportionately from any future price appreciation. Smaller private miners, lacking access to capital markets, are increasingly selling their machines to public companies or signing hosting agreements that effectively make them contractors rather than independent operators.

The long-term question this raises for Bitcoin is whether the mining ecosystem will remain sufficiently decentralized. A mining industry dominated by a handful of publicly traded corporations introduces risks that are different in character from the geographic concentration risks that preceded the Chinese mining ban. Corporate governance, regulatory compliance requirements, and the possibility of government pressure on publicly listed companies are concerns that warrant ongoing attention from those who care about Bitcoin's censorship-resistance properties.

The fourth halving did not break Bitcoin mining — it has never broken it. But it has continued the inexorable process of professionalizing and concentrating an industry that began with hobbyists running CPUs. The next halving in 2028 will face a sector that is leaner, more institutionalized, and more dependent on transaction fees to make the economic math work.

"Bitcoin Mining After the 4th Halving — How Proof-of-Work Economics Are Shifting"

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