Sometimes it could be a good decision some other times, it could be the worst decision. I can relate with either of the two scenarios where I just bought a not popular coin and the next day it just increase so high that I was even surprised. The other not so funny experience I just went all in and everybody in the market just decide not to buy this particular coin and gradually exchange sites start delisting the coins while no one is interested in buying. More detail is needed before taking any investment decision.
Small capped altcoins have small trade volumes and there is a huge risk of getting dumped by bag holders. Imagine, one bag holder can dump his tokens to get into bitcoin or ether, this causes a huge loss for you.