Bitcoin mining difficulty posts biggest drop since ASIC era by Wolfie Zhao
https://www.theblockcrypto.com/linked/83325/bitcoin-mining-difficulty-largest-drop-asic-era
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The difficulty drop is a result of the decline of the average total computing power racing on the network in the last two weeks as many Chinese miner operators have unplugged their machines to migrate to fossil fuel power stations from hydropower plants.
The decline of bitcoin's mining competitiveness will push up bitcoin miner's daily revenue per terahash second of computing power in the coming days, which is already reaching its highest point since the block reward halving in May.