There is something called seasonal trading, what this means is that there are assets from which their demand changes during the seasons, for example people need more oil and other types of fuel to keep themselves warm during the winter, now you may think that since seasons chance depending on the hemispheres there would not be an opportunity for seasonal trading there, but it does, as more people are living in the north than in the south hemisphere, and something similar happens with bitcoin, since we know when the halving will come with a very high degree of accuracy this causes something resembling seasonal trading, but instead of happening in a single year it happens on four years.