Whenever I see the word "guarantee" in every investment, I always think that it's a scam because that's the word most of the scammers are using.
I'm not saying that Howeycoins is a scam just because they used the word "guarantee", but I'm just pertaining to that word.

You are right to think that way and Howeycoins was actually a promotional campaign on how scam projects operate. If you tried to make a purchase this is the message you get -
https://www.investor.gov/ico-howeycoinsIf it looks like a scam and smells like one, it most likely is one.