Yep. There is data that supports what you're saying. The truth is the miners are just like everyone else with an additional incentive to sell to stay in business. Some of them sell more often and some try to hold on longer. There's no universal strategy.

The real kicker though is that the demand coming from the ETFs is a lot higher (some reports say 6x to 10x) more than what the miners are producing. The data shows most of the selling is actually still coming from GBTC but it's only a matter of time before they run out.