Market seasonality


I've been thinking about the seasonality of the market lately. Some people say that the market have a monthly seasonality, and others claim that it has an annual seasonality. What do you think ?

I see why an annual seasonality makes sense in some other domains such as meteorological datas, but how can we interpret it in the market ?

Thank you,
A common example for year-over-year market seasonality is holiday seasons. Some retail companies will always have more sales in Nov / Dec because that's when families buy more gifts. It makes less sense to compare Nov/Dev sales to Sept/Oct and say that is growth (monthly seasonality). it makes more sense to compare Nov/Dec 2020 to Nov/Dec 2019. Or Q4 this year to Q4 last year.