The y series have become a trending topic on most social media.
Is this so called "y series" just your own invention or not? If yes then that's a witty way to sum them up in all fairness. However, there's nothing wrong if the name of their platform starts with letter Y. Such thing is not a big evidence for them on becoming scam or not because there are previous scams which don't start in letter Y obviously 
. Just a coincidence I guess. Please be cautious of your investment. Don't get carried away with the hype and follow up with them all incase there is a red flag. So you don't get caught.
FOMO is okay, that's what I've learned in the past. Bitcoin and reputable alts are enough for me.