I think big miners will drop the price to $4,000 or less precisely to try to make small miners give up. So i don't think the cost of production has any relation with the last rebound
This is a classic move by monopolies, they can sustain losses for far longer than any small business driving them to sell their operations to them and then making the prices to go up again, and since they can do this at will then they can prepare for that scenario and store a lot of coins and prepare themselves and suppress the price for months and maybe even for a full year driving most small miners to bankruptcy while they laugh at us and our inability to comprehend what it is actually happening.