A sharp drop in the Bitcoin blockchain's hashrate, down 10% on Sunday, during this week’s U.S. winter storm, is offering a real-time stress test of a concern long flagged by researchers: mining centralization has turned local infrastructure failures into system-level risks.

Hashrate is the amount of computing power available to process transactions required to keep the Bitcoin blockchain running at any given moment. When it drops sharply, the network has less room to process transactions, increasing the risk of delays before the difficulty resets.

While the Bitcoin blockchain continued to operate through the storm – as only 10% of the blockchain's hashrate went offline – a growing body of academic research suggests its exposure to such events has grown.

In a 2021 working paper, Bitcoin Blackout: Proof-of-Work and the Risks of Mining Centralization, researchers Philipp Scharnowski and Jiahua Shi found that a regional mining outage in China in 2021 led to longer block times, higher transaction fees, and degraded market quality, showing how concentrated mining can turn local power failures into network-wide disruptions.

That research helps contextualize why rising concentration in BTC mining matters, as block production has increasingly clustered among a handful of dominant pools.

The Mining Centralization Index indicates that block production is now dominated by a small number of pools, reducing the network’s ability to absorb localized shocks.

Over the past two years, the top two mining pools have often controlled more than 50% of Bitcoin’s hash rate, while the top six pools have consistently accounted for roughly 80% to 90% of all blocks, leaving much of the network’s transaction processing in the hands of a few operators.

For now, markets appear unfazed, as BTC barely moved on the day, but the episode highlights how the Bitcoin blockchain's growing mining concentration can turn physical infrastructure failures into system-level stress without immediately showing up in the price.