If a coin is still very new to the market and it is having a low trading volume at the same time, I think it is a good time and avoid opportunity to acquire more.
Although, this is not applicable to all coins. Based on what I have seen so far, a coin that has a good product, perhaps actively under development and has such experience while listed, investors most times make good use of the opportunity, by acquiring more.
Remember that the bitcoin start on a low trading or even low supply before. It's up to the project admins and participants if they continue to develop this specific alternative coins.