Miners are cashing in most of their mined BTC (3600~4000 every day) to pay their bills as difficulty increasing mining is getting more and more costly.
4000 BTC at 400$ each amount for about 1.6m$ every day.
You need a really strong buying support to get over that.
If you sold the coin, you are realizing the loss, thus would never make it back. So the wise move is to stop the miner so that you don't need to pay the bills, and then buy the coins
Including previous holder's cash out, there should be several thousand BTC for sell every day, but 1.6m$ every day is really nothing if you comparing with FED printing 2.5b$ every day