I think the reason why we are getting such a drop is because people are sitting at negative ROI and it leads to these sell pressures.

Basically if you ever frequent the ethereum reddit most people on there basically dump their ETH for USD as soon as they get a payout from the pool because they need to pay for their 1080Ti and their electricity.

In a panicky market such as today, there are less willing buyers but the same amount of miners which dump prematurely and cause these huge 25% declines.

Also there are people who bought all their GPUs on Newegg and bought $20K worth of equipment and are paying interest at 20% APR which is like $300 a month in interest which isn't even enough from their mining profits. The same happened in 2014.