Key Highlights
- The Bitcoin network briefly split into competing chains when AntPool + ViaBTC and Foundry USA mined parallel blocks 941,881 and 941,882 nearly simultaneously due to propagation delays.
- Foundry USA mined seven consecutive blocks (from height 941,879 to 941,885), accumulating more proof-of-work and orphaning the rival chain under Nakamoto consensus. No attack or failure occurred.
- The network stabilized instantly with zero impact on transactions, security, or price ($71,000). The event underscores probabilistic finality, the rarity of multi-block reorgs, and the role of hashrate concentration (30% for Foundry) in normal mining dynamics.
On March 23, 2026, the Bitcoin blockchain underwent a rare two-block reorganization at height 941,880—highlighting the competitive and probabilistic nature of its proof-of-work consensus. The incident began when competing mining pools briefly split the network into two parallel chains of equal length.
AntPool mined block 941,881, which ViaBTC extended with block 941,882. Simultaneously, Foundry USA produced its own versions of blocks 941,881 and 941,882, creating a fork.
Foundry USA then extended its chain by mining blocks 941,883 through 941,885, ultimately producing seven consecutive blocks from height 941,879 to 941,885.
This longer chain accumulated more proof-of-work, becoming the canonical ledger under Nakamoto consensus. As a result, AntPool and ViaBTC’s blocks were orphaned and discarded as stale, a normal resolution rather than an attack or failure.
Bitcoin developer and observer @0xB10C documented the event with a detailed diagram, noting the timestamps were separated by mere seconds due to network propagation delays.
Single-block reorgs occur regularly, but two-block reorgs are uncommon, reflecting Foundry’s substantial hashrate share—often around 30% or more—which increases the probability of such streaks.
The network stabilized quickly with no impact on transactions, security, or Bitcoin’s price (trading near $71,000). Experts emphasized that this demonstrates Bitcoin’s robustness: nodes always follow the chain with the most cumulative work, and deeper confirmations grow exponentially more secure. While some community members raised concerns about mining centralization and potential “selfish mining,” analysts described it as expected dynamics in a decentralized system, not malice.
The event serves as a reminder that Bitcoin prioritizes probabilistic finality over instant immutability, reinforcing the importance of waiting for multiple confirmations on high-value transfers.
Also read: Bitcoin Reserves Near Record Lows While ETFs Stage 2026 Comeback
