Looks like a clear trend to me

better not to sell anything at these levels, the trend is going to continue hopefully in 2022.
Though actually, if this is a trend that's clear, then it's pretty clear that after a 4-year streak of gains, it took a nosedive and was less than 50% of the Christmas price 2 years later. You'd have needed to wait for 2020 Christmas to see gains on 2017.
Now if we presume this is a trend, then this is already the 4th consecutive annual streak of gains since 2018. Another 2 Christmases below 50k? Works for me to wait for 2024 to see 75k. Stack those sats!