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?
Satoshi and possibly a few other early miners are still sitting on their 50BTC block rewards. I'm sure a quick scan on the blockchain will reveal idle coins from that era.