The 3.125 BTC Era Begins: How Miners Are Navigating the Fourth Halving at Block 840,000

The Hardware/Software Landscape

On April 20, 2024, Bitcoin miners witnessed a watershed moment as the network completed its fourth halving at block 840,000, reducing the block subsidy from 6.25 BTC to 3.125 BTC. With Bitcoin trading at approximately $64,994 on the day of the halving, the immediate revenue impact translated to a drop from roughly $406,000 per block to $203,000 in subsidy alone — a seismic shift that mining operations had been preparing for since the previous halving in May 2020.

The hardware landscape entering this halving was markedly different from previous cycles. Application-specific integrated circuit (ASIC) manufacturers like Bitmain, MicroBT, and Canaan had pushed chip efficiency to new thresholds, with the Bitmain Antminer S21 series achieving 17.5 joules per terahash (J/TH) — a substantial improvement over the 30+ J/TH units that dominated just two years prior. Mining operations that had invested early in these next-generation machines found themselves with a critical efficiency advantage as the reward reduction reshaped the competitive landscape.

Software optimization also reached new heights. Mining pool operators implemented advanced payout schemes, including pay-per-share (PPS) and full pay-per-share (FPPS) models, to attract hashrate in the post-halving environment where every satoshi of efficiency mattered. Firmware customizations, such as Braiins OS and vnish, allowed operators to undervolt and overclock their ASICs, squeezing additional performance from aging hardware that might otherwise become unprofitable.

Hashrate & Difficulty

In the weeks leading up to the halving, Bitcoin network hashrate surged to unprecedented levels, peaking above 650 exahashes per second (EH/s). This represented a staggering increase from the approximately 180 EH/s recorded at the time of the third halving in May 2020, underscoring four years of relentless infrastructure expansion by both public and private mining entities.

The difficulty adjustment mechanism — Bitcoin built-in economic equalizer — played its usual critical role. With blocks being mined faster than the 10-minute target due to elevated hashrate, the network difficulty rose consistently in the lead-up to block 840,000. Following the halving, analysts anticipated a temporary dip in hashrate as less efficient miners disconnected, followed by a difficulty decrease that would partially restore profitability for remaining operators.

Foundry USA and AntPool continued to dominate the mining pool landscape, collectively controlling over 50% of global hashrate. The concentration raised familiar decentralization concerns, though the overall distribution remained more balanced than in earlier eras when single pools occasionally exceeded 40% alone. F2Pool, ViaBTC, and Binance Pool rounded out the top tier, each adapting their fee structures to retain miners navigating the post-halving squeeze.

Profitability Metrics

The hashprice — the revenue a miner earns per terahash per day — dropped dramatically from approximately $0.08-0.10/TH/day before the halving to roughly $0.04-0.05/TH/day immediately after. For operations running older-generation hardware like the Antminer S19 series (95 J/TH), this placed many squarely at or below the breakeven threshold, particularly in regions with electricity costs above $0.05 per kilowatt-hour.

Transaction fees emerged as a crucial revenue supplement during this halving. The launch of Runes — a new protocol for creating fungible tokens on Bitcoin — coincided with the halving event, driving a significant spike in on-chain activity. Bitcoin transaction fees briefly spiked above $100 per transaction in the hours surrounding block 840,000, providing miners with a substantial but volatile revenue buffer that partially offset the subsidy reduction.

Mining companies with access to sub-$0.03/kWh power contracts — primarily those in the Middle East, Latin America, and select North American regions with renewable energy agreements — maintained comfortable margins even at the reduced block reward. Publicly traded miners like Marathon Digital, Riot Platforms, and CleanSpark had spent the preceding months stockpiling BTC and expanding capacity at favorable energy sites, positioning themselves to weather the halving storm.

Environmental Impact

The fourth halving reignited debates about Bitcoin energy consumption, though the narrative had shifted considerably. By April 2024, an estimated 50-60% of Bitcoin mining utilized renewable energy sources, driven by the economic imperative of accessing the cheapest possible electricity. Solar and wind installations in Texas, geothermal operations in Iceland and El Salvador, and hydroelectric power in regions of China neighboring countries had become integral to the mining ecosystem.

The halving itself paradoxically supported environmental efficiency arguments. With reduced block rewards, only the most energy-efficient operations could survive, creating a natural selection pressure that favored renewable and stranded energy sources over fossil fuel-dependent setups. Mining companies increasingly published sustainability reports and pursued carbon offset programs, responding to both regulatory pressure and institutional investor expectations.

Strategic Outlook

The post-halving landscape points to continued industry consolidation. Smaller, less efficient miners face pressure to either upgrade hardware, relocate to cheaper energy markets, or exit the industry entirely. The companies that survive this transition will likely emerge leaner, more efficient, and better positioned for the next cycle — when many analysts expect Bitcoin price appreciation to more than compensate for the reduced block subsidy.

Looking ahead, the fifth halving — projected for 2028 — will further reduce the block reward to 1.5625 BTC, making mining economics increasingly dependent on transaction fee revenue and BTC price appreciation. The industry trajectory suggests that mining will continue its evolution from a speculative venture to a sophisticated industrial operation, with energy procurement and hardware management as the primary competitive moats.

Disclaimer: This article is for informational purposes only and does not constitute financial or investment advice. Mining profitability depends on numerous factors including hardware efficiency, electricity costs, network difficulty, and Bitcoin market price. Always conduct thorough research before making mining investment decisions.