I cant access hashnest as I can't log in (due to broken 2fa on their side).
But when I was there there were a few things to consider.
The price changes througout the day, at 09:00 utc there would be a lot of volume and such a lower price would be observed, later on there would be less volume and less competition so the price would go up higher at about 21:00 utc it used to be a pain and a good thing. One was that it alsmost always happened so you could profit off the market a bit. Another was, if you wanted to pull out large amounts then you'd do it in the morning (as apposed to me who kept doing it in the evening and dropping the market prices quite substantially accidentally)...
It is possible they might be selling hashpower over the market though. What's the price per ghs or ths there?
Well thats the problem with hashnest, Apart from the original buyer/sellers! Hahsnest is manipulative in price, 1TH right now 0.00907000! Their are TOO MANY 1TH's being sold on hashnest which are CLEARLY being sold by hashnest administration and not from original sellers, Their are VERY FEW which are being sold by original sellers. If hashnest is not manipulative on the prices of THs, Lots of people can make money by trading THs only!
P.S : I will see at 21:00 UTC and see if any prices would go up at that time! But to me, Whenever I try to sell my hashes, Someone else immediately is selling 1TH at lower price above me then in few minutes more 1TH lower prices, Its as if hashnest is deliberately putting all prices down so people should panic and sell at cheaper prices and they buy all the hashes themselves at cheaper prices and then sell back at higher prices etc!