Is there any analysis on the % of miner block rewards (BTC mined) that have been spent? How much BTC do miners keep in reserve?

With the halvening coming up, I was wondering if anyone has tried to parse out how much BTC miners have sold and how much they've held onto. I realize this is technically impossible to calculate to 100% accuracy, but I'm sure someone has gotten reasonably close using popular exchange deposit addresses, % of coins moved x amount of times, etc.I've looked around, but haven't found anything solid on the subject. Has anyone found or done this analysis themselves? I imagine it would not only be difficult to research, but also difficult to be certain about. Either way, even a close estimate could tell us a lot about expected price behavior post-halvening. If miners maintain large BTC (not USD) reserves, it may take a very long time before the price is impacted by the drop in supply. via /r/Bitcoin http://bit.ly/2TnNRHY