Last weeks miners have been accumulating bitcoins and only some of them were sold when prices recently reach 9700$. Two days ago miners started to accumulate bitcoins again. When will they sell some of them? As soon as they see higher prices. As a consequence, there is strong sell pressure waiting for short-time higher prices and this process will soften and even hinder any potential rally.
Komen:
Miners have just started to sell bitcoins again after several days of stockpiling. They now sell more than what they mine (100,6%), thus slightly reducing its stock. This means they think that current BTC price is a high short-term (several weeks) price. Necessarily, at least some of them expect a short-time downturn, hence the selloff.