Holy hashrate, Bitmain!
My theory with drop in difficulty lately it's my initial A3 buyers decided to sell the units on ebay etc and the units were not running while being shipped. Now they are all coming back online and difficultly will return.
The drop in difficulty was due to block times. This spike, whatever it is, is equivalent to 3600ish A3's being turned on.
Yes. Confirm the calculation of ~ 3400-3600 A3s coming online within very short timeframe, ie. 2hrs. If this is the source, then only one capable of that is BM.
There's been a decent amount of speculation as to why Bitmain is selling batch 2 at such low prices. Look at what Halong Mining claims*** to do (they still have not shipped a single unit of their SHA256 miner to date so this is very TBD) with a miner that can hash SHA256 at 16TH/s, slightly higher than the S9. If they are now claiming that they have a Sia miner at 3.5TH, I would not be surprised if Bitmain has an "A3+", "A5", whatever you want to call it around the corner. I don't think Bitmain is dumping stock because of the SC1, I don't think they're dumping because of the B52... I think they've been able to massively iterate over their first Blake2b miner and are going to crank the game up a few notches here soon.
They are trying to beat everyone to market and unload stock. They can manufacture 16nm ASIC miners at under $500 cost,,,, so they are hugely profitable. My speculation is they are trying to clear out warehouses to make room for new models to be available mid-year.
Due to their government rule, it maybe banned to mine in China. If they have to move it all to other country and got custom taxed to mine with the "same miner", its better to sell it all and put new generation miner for the new farm with better performance and make it "undervalue" since custom cant find price for it.