Foundry Pool Triggers Temporary Bitcoin Fork

The world’s largest Bitcoin mining pool, Foundry, mined seven consecutive blocks, causing a temporary network fork. The event occurred when multiple mining pools discovered blocks almost simultaneously. The Bitcoin network automatically resolved the split, but the incident highlights rising concentration risks in the crypto mining industry.

A streak of mined blocks led to a network fork

Foundry mined seven consecutive Bitcoin blocks from height 941879 to 941885. Before block 941881, the pool had already mined four blocks in a row.

At block height 941881, Foundry and AntPool discovered blocks almost simultaneously. The time difference was just 12 seconds, which triggered a network split.

The situation evolved further:

• ViaBTC extended the AntPool chain with a new block;
• Foundry created an alternative chain at the same height;
• two competing chains briefly coexisted.

As a result, the Bitcoin network temporarily split into two branches before resolving the conflict.

Competition for blocks has increased the likelihood of forks

The fork occurred due to high competition among mining pools. As hashrate increases, the probability of simultaneous block discovery rises.

Key factors include:

• growing concentration of hashrate among large pools;
• minimal time gap between block discoveries;
• increasing total network computing power;
• intense competition for block rewards.

The Bitcoin protocol selects the chain with the highest cumulative Proof-of-Work. In this case, Foundry’s chain prevailed because it extended faster.

The market will face growing influence from large mining pools

The event did not threaten Bitcoin network security. However, it revealed structural risks tied to mining concentration.

Potential implications:

• increased focus on mining centralization;
• stronger influence of major mining pools;
• higher likelihood of orphaned blocks;
• temporary delays in transaction confirmations.

Blocks mined by AntPool and ViaBTC were orphaned. Their transactions returned to the mempool, and miners received no rewards.

Mining is becoming increasingly dependent on scale

The incident highlights ongoing changes in the crypto mining industry. The market is becoming more concentrated and dominated by large players.

Key takeaways:

• large pools are gaining greater control;
• competing chain events may become more frequent;
• efficiency and scale are becoming critical;
• centralization risks continue to grow.

As a result, Bitcoin mining is moving toward consolidation. Network stability remains intact, but the balance between decentralization and efficiency is becoming increasingly important.

Read also: Foundry to Launch Zcash Mining Pool in 2026