Bitcoin’s mining difficulty fell 7.7% on March 20 to 133.79 trillion at block 941,472, marking its second notable reduction of 2026.

Why difficulty fell

The adjustment followed slower block production over the previous 2,016 blocks.

CloverPool data showed average block times of about 12 minutes and 36 seconds, well above Bitcoin’s 10-minute target, prompting the network to recalibrate lower.

Mining difficulty had been around 145 trillion in mid-March and roughly 148 trillion at the start of the year.

A lower difficulty means miners need less computational work to find a valid block, which can slightly improve revenue per unit of hashrate.

Hashrate and miner economics

Bitcoin automatically adjusts difficulty to keep issuance close to one block every 10 minutes.

When network hashrate rises, difficulty increases to prevent blocks from being mined too quickly.

When hashrate falls, difficulty moves lower, making it easier for the remaining miners to earn rewards.

In February, difficulty also dropped after weather-related disruptions in the United States temporarily pushed large mining facilities offline.

It later rebounded by about 15% as those miners returned.

The next difficulty adjustment is currently estimated for April 3.

Miners shift toward AI

The latest reset comes as several public miners continue shifting capacity toward AI and high-performance computing.

Core Scientific, MARA Holdings, Hut 8 and Cipher Mining have all expanded or explored AI-related infrastructure as power costs and post-halving mining economics remain under pressure.

On Feb. 21, Bitdeer sold 943 BTC from reserves and reduced its corporate holdings to zero.

Its March 21 update said those bitcoin holdings remained unchanged at zero.