An old or new coin has the same risk attached.
That's not true. A coin that has been around for quite some time will have more trust in the community because investors would know it isn't a scam or won't run away with their funds. After all, it has been years since the coin was first listed in the market and it has been doing pretty well.
However, if we talk about new cryptocurrencies, there is always a fear in the mind of an investor that the coin might turn out to be a scam any time, and that is because we see that happen a lot in the industry where a project is heavily marketed, shown to be among the best, and after a lot of people invest in it, the developers dump their share of the coins in the market and abandon the project.
So in general, old cryptocurrencies are considered to be safer than the new ones.