This is not always the case. In most of December last year, the market was red, and the rising market was only short-lived, so in general, last December was still a downhill market, we should not just see the green market and ignore the red market.
We don't know how will the price moves but all we know is that there are o ly two options of movement, it is either the price will pump creating or generating more profits that might go over the reigning ATH or another dump that might be lower to the lowest price of the year. But despite that dump, lets look at it at the good side, a lot of people would be able to invest at that time thus making the price rise again.