As you can see from the above chart, currently BTC price is below its mining cost.
when mining costs are lower than Bitcoin's market value, more minors will join.
when mining costs are higher than miners' revenue, the number of minors will decrease (which is the case here.)
and also historically whenever the Bitcoin price moved below the mining cost, we saw an immediate bounce back. miners are not ready to sell their bitcoins for loss, so the sell volume decreases when the bitcoin price is crashed below its mining cost.