There is something going on in the world of btc being done at big levels.
I see btc diff dropping more then 20%
hashrate is about 6,700,000,000 for the current diff of close to 886,000,000,000
I can do longer find current diff numbers live time
and current hash rate according to viabtc is at 4,700,000,000
Why are the live time diff trackers off line?
My guess is people are switching to mine bitcoin cash due to low difficulty - read
https://www.coindesk.com/bitcoin-cash-returns-profitability-amid-mining-adjustments/