2025 was a transformative year for Bitcoin mining, with network hashrate climbing from 801 exahashes per second (EH/s) at the start of the year to over one zettahash per second (ZH/s) by early September. This milestone—crossing the zettahash barrier—means the network performed on the order of 10²¹ SHA-256 calculations every second, adding three orders of magnitude compared to the exahash era in 2016. The achievement solidified Bitcoin’s security, as controlling more than half of 1 ZH/s would require hardware and energy investments worth tens of billions of dollars.
Hashrate Growth and Difficulty Adjustments
January began with a harsh winter storm that cut power to some mining operations, prompting the first difficulty decrease since late 2024. Despite low transaction fees—the lowest since 2012—the network’s computing power held firm and grew steadily. From January to September, hashrate increased by roughly 37%, adding about 200 EH/s over the year.
Mining Economics Under Pressure
Hashprice, the revenue metric for miners, started 2025 at ~0.00058 BTC per PH/s per day (around $54.45 per PH/s/day) but declined to the mid-$30s per PH/s by November and just under $40 in December. Thin fees, rising global competition, and relentless investment in next-gen ASICs squeezed less efficient operators, while large-scale players with cheap power and cutting-edge hardware strengthened their positions.
Mining Pool Dominance: Foundry USA Leads
Between January 1 and December 1, the network produced an estimated 47,664 blocks. Foundry USA dominated with a 30.46% share (≈14,518 blocks), followed by Antpool (18.29%, 8,718 blocks), ViaBTC (13.04%, 6,215), and F2pool (10.74%, 5,119). The top four pools controlled roughly two-thirds of all blocks, reflecting increasing industrialization. Mid-tier pools such as Spiderpool (5.98%), MARA Pool (4.91%), Secpool (3.57%), and Luxor (3.30%) also made notable contributions. Binance Pool accounted for 1.91%, independent miners for 1.85%, and smaller pools filled the rest.
Year in Review: Security at an All-Time High
By December, 2025 had clearly leveled up Bitcoin’s security. Even with hashprice sliding and operating costs stubbornly high, miners kept pushing hardware limits. Efficient operations weathered the tough revenue environment, while less efficient ones consolidated or shut down. The result: Bitcoin’s security reached its highest level ever, backed by an unprecedented wall of computational power. The zettahash era has arrived and settled in.