Yes in case of holding for a long time the value of the currency often decreases a lot in that case even if you make a long-term investment it is better to invest for a short period of time without keeping it for too long. But there is nothing to be sad about even if you miss the profit wait patiently the currencies will rise higher in the future crypto market means rise and fall.
For altcoins,,, always for altcoins. For Bitcoin it is always long term and sure you can make some money trading it for profit but in the end everything about Bitcoin points to long term value for holders and users. Altcoins prove there is nothing in their markets except for speculators who of course only think in the short term.
Do not see them as missed opportunities. Bitcoin opportunity is alive and well.
The point is that there is no panic in seeing the price in the exchange, often the panic makes people afraid of big losses, if invested in Bitcoin maybe it will always be a gem instead of holding an altcoin, because everything will remain an altcoin even trash in the future, It depends on the development of the project, but everyone does not want to take high risks regarding their investment, because most people are more likely to be more interested in investing in Bitcoin because it has enough sensation for the future and will potentially become Fanstastic value in the future ...
And it all depends on your abilities !!