I just took a peak at the ethereum difficulty chart today, and there has been a significant drop of hashrate (>50%) a couple of days ago. It seems to have happened over the course of just a day.
I can’t see a corresponding rise in the Zcash difficulty chart, though. So where did that hashrate go? Any chance we will be seeing a big rise in Zcash mining difficulty in the near future?
The drop I think was down to the Byzantium hard fork for Ethereum which lowered the payout per block - but yes a big drop. It also seems that ZEC difficulty has dropped a bit too.
Where all the mining power has gone I don’t know - but perhaps there are a few power stations sitting idle due to miners having switched off their rigs too - but doubt it…