Bitcoin mining difficulty dropped around 7.7% on March 20 to 133.79 trillion, marking the second major adjustment lower in 2026.
The decline reflects reduced network hashrate, with average block times slowing to about 12 minutes 36 seconds compared to the 10-minute target.
Lower difficulty reduces the computational work needed to mine blocks, slightly improving profitability for miners who remain operational.
The adjustment follows earlier volatility in February when weather disruptions temporarily shut down US mining facilities before hashrate rebounded.
At the same time, miners are facing growing competition from artificial intelligence data centres, which are increasingly competing for power resources.
Companies including Core Scientific, MARA Holdings, Hut 8 and Cipher Mining have begun reallocating infrastructure toward AI workloads to improve returns.
The shift highlights ongoing pressure on mining economics, with some firms reducing operations or selling Bitcoin reserves as profitability tightens.
At the time of reporting, Bitcoin price was $69,271.87.