I'm guessing these Chinese miners have free electricity from the government and they have upgraded gear that isn't even on the market yet. Like even with these low prices difficulty hasn't really even gone down, this is insane.
punch in 2 cent power and most coins look very good.
punch in 3 cent power and most coins look good.
punch in 4 cent power and some coins still work.
So if you have these power costs you buy used gear from those that have busted out and for now mining works for you.
The reality is a lot of people don't have 2-4 cent power and they are dumping their gear.
So a guy with big farm and low power just smiles.
I can only hang in and still mine at this due to having solar power deals in my state of NJ (a very good solar power state)
I have access to "free" power basically I put up gear and split the coins.
so if I put up 10 s9's I get the hash from 5 s9's and the solar guy gets the hash from the other 5.
5 s9s = 70th and earn 321 a month so in 7 months I get 2200 which is roi for them.
My issue is the solar I have access to is about 55kwatts or about 560th I am capped at this for now.
so I get 280th a month or 1240
the solar guy gets 280th a month. btc diff is flatlined for now. as I predicated in this thread
https://bitcointalk.org/index.php?topic=5043713.0on oct 4th 2018
https://bitcoinwisdom.com/bitcoin/difficultyOct 04 2018 7,454,968,648,263 4.23% 53,364,744,228 GH/s
Feb 10 2019 6,061,518,831,027 4.25% 43,390,041,906 GH/s