Avalanche founder Emin Gün Sirer has reignited debate over Bitcoin’s long-term viability, warning that shrinking mining rewards may pose a more serious threat than quantum computing or rival tokens. His remarks, shared across multiple outlets on May 10, 2026, shift focus to the economic sustainability of Bitcoin’s proof-of-work model as each halving cycle cuts block rewards by 50%.
Bitcoin miners secure the network by solving cryptographic puzzles, receiving newly minted coins and transaction fees as compensation. However, the block subsidy halves roughly every four years, forcing miners to rely increasingly on fee revenue. Sirer argues that unless transaction fees rise dramatically, this trajectory could undermine the network’s security budget. CoinShares recently estimated that 15% to 20% of the global Bitcoin mining fleet may already be unprofitable under current conditions, with older hardware and high-cost operations most at risk. The report noted that Q4 2025 was the toughest quarter for miners since the April 2024 halving, with hashprice near five‑year lows and listed miners’ average cash cost to produce one BTC hovering around $79,995.
Sirer suggested a potential technical remedy: a pre‑consensus layer that could reduce the load on Bitcoin’s base network, a concept connected to technology developed within the Avalanche ecosystem. Yet such proposals face strong resistance from Bitcoin purists who oppose fundamental protocol changes. Meanwhile, former Binance CEO Changpeng Zhao commented that Bitcoin could theoretically be replaced by superior technology in a distant future, but clarified that it currently functions as global money and remains deeply embedded in the financial system. Some accounts had sensationalized his statement, falsely claiming he predicted Bitcoin’s disappearance.
The renewed focus on Bitcoin’s mining economics comes as institutional capital continues to flow into the market, altering traditional four‑year cycles and amplifying attention on long‑term network resilience.
