I bought 4 TH/s of Umisoo farmshares for 2 BTC about a 3 weeks ago and 5 more for about 0.6 BTC yesterday. I guessed with BTC hitting an alltime low and mining operations getting stopped, prices for GH/s would never be cheaper than yesterday, so I took the risk.
I am also counting on BTC recovering (which it is right now), then waiting for a good opportunity to sell my TH/s as soon as their value goes to around 0.3 to 0.35 BTC (I doubt they will return to the old price of 0.5) and reinvest that in the AntS4 operation when their price comes down.
I think it is important not to hang on to the Umisoo shares for too long now, as we just saw that 1W / GH/s is not sustainable anymore, unless BTC returns to the 350$+ price range.