Buyers are happy to buy bitcoins from sellers because they see chance to get profit and otherwise, sellers are happy because they either take profit by selling their bitcoins or luckily cut loss or avoid loss before a possible market crash.
Sellers are indeed joyful when they sell and make some little profits until they sell and instead of the price to fall for them to rebuy again it ended up even skyrocketing to a length that they will find it difficult to buy back since the price didn't DIP as they so wished for. This is why trading is shit because at a time when the market is favorable with the strategy of buying low and selling at highs, when an opportunity does not surface again such as a price DIP for a rebuy they finally end up not buying in the end which means they will remain stagnant and disoriented. This is why accumulating and hodling is the sure way to go because since you are hodling for a longer time, it will grant you the opportunity to acquire as much bitcoin in your portfolio (even buy at DIPs) coupled with the profits that comes along with it. Let's take El Salvador for example, they made bitcoin a legal tender in 2021, then fast forward to late 2024 when the price of bitcoin hit $100k, they already got doubled of the amount they acquired in bitcoins even when it's not up to a cycle since they started hodling. Isn't that a good investment practice of buying and hodling for future growths?