The BTC mining market in December is a bit cold. The next round of difficulty retargeting is set for the 11th, and it is expected to rise again, but the computing power price is quickly falling to historical lows. This is not good news for miners — higher mining difficulty means fewer coins produced for the same computing power, while the drop in computing power prices directly compresses profit margins. At this point in time, miners' profitability is facing a double squeeze, and many small and medium-sized mining farms are likely going to need to recalculate their accounts.