Mining has become a business and it’s growing. It has daily expenses and for that miners need to sell their BTC to cover up electricity bill and other cost if exists. But is there any known miner who has not sold their BTC for a single time who is mining for a long time now? We know there are addresses which haven’t moved their BTC for a long time. Is any miner included in the list?
More likely, that is not possible considering how far bitcoin has reached already. Most or almost all of the miners probably have spent some of their bitcoin already. If ever a miner managed to hold their bitcoin for a very long time up until now, there's a high chance that he is a whale right now capable of manipulating the market for a bit on every action he makes. Sooner or later, we will see and witness more miners spending their bitcoin due to the unforeseen situations like crisis in bitcoin. For now, all we can do is try and do our best not to sell what we are mining since bitcoin is not in a good shape at the moment.