But eventually those who have held Bitcoin all this time will sell, and as large new buyers enter the market and mining rewards halve, the quantity supplied will decrease, and then prices should start rising again.
Of course, this process takes some time, so I do not expect that we will witness a significant rise immediately after the halving, as some think, but it is certain that we will witness it in the end.
However, if they will chose to hold even longer, that would mean bigger profits in the future. Bitcoin is always highly volatile, and that volatility is the one big reason why a lot of us are even excited to hold even longer knowing bitcoin price will always appreciate no matter how often its price fluctuations.