Bitcoin Hashrate Recovery Hides Centralization Risks

Bitcoin's hashrate has recovered from its low in early 2026, climbing to 920 EH/s in September. This recovery comes after a drop caused by severe winter storms that led to high electricity prices and operations stalling. The network's computational power is still below the October 2025 peak of 1.15 ZH/s. Bitcoin trades at $77,133, with difficulty levels near 127.45 trillion. Foundry USA dominates the mining landscape, controlling 26% of the total network power with 244 EH/s.

The concentration of hashashrate among a few large entities raises concerns about centralization risks. The Nakamoto coefficient is 3, indicating that three pools control over half the blocks. This dominance persists despite previous volatility and the network's resilience. Foundry USA uses the Full Pay Per Share (FPPS) payout method, which pays miners a fixed amount for each valid share submitted.

The cost of a 51% attack on Bitcoin exceeds $7.9 billion, making it a financially daunting task. However, this vulnerability exists due to the Stratum V1 standard allowing pool operators to decide which transactions to include in a block. The adoption of Stratum V2 may provide enough decentralization to negate the power of the largest pools.