I believe that's the dynamics of the market and one thing you most know is that there is ups and downs when it comes to investment and there is every possibility that after buying a certain coin it will likely appreciate as time goes by while in most cases it will depreciate after you have bought but so long as you invested on a good coin no matter how the price drops it will surely bounce back to it normal price.
When you say that, I only imagine one coin, namely Bitcoin, because so far everyone has seen that investing in Bitcoin in the long term is always more likely to win after the price of Bitcoin increases again and this has been proven in several market cycle. And I think investors who still like to invest in Bitcoin in all market conditions, of course they will not be so easy to let go of their investment and they will even prefer to wait for the price to increase again even though they have seen the price of the Bitcoin they invested in decrease.
this is one of the main reason why some folks make the mistake of investment into any coin they see out thier with the mentality that as long as you invest into it, that with time it value would increase greatly. The reality is that such kind of mentality would only put you in a position where you end up investing in a dead projects that's even long gone. Bitcoin stands out as the surest investible long term asset. In the past, Bitcoin was valuable and at the presence it's still the most valuable asset and even in terms of having the greatest prospects even outside of the whatever digital asset that's out there, Bitcoin has stood strong and has even become more valuable than precious metals and gold.
Maybe in the future there can possibly come a digital asset that could get close to having the value that Bitcoin has had overtime , but even if such eventually cokes out, it's most likely going to be a model that's made to having the replica of Bitcoin.
It's even very disrespectful to make any comparison between Bitcoin and what's now known as crypto or other coins. If you are only able to buy a $5k worth of Bitcoin and leave it in your wallet, you can comfortably relax for couple of years without necessarily coming back to check if Bitcoin has gone valueless or something like that, but you can't make such kind of bet with what's now flying here and there as alt.