How are prices and market caps of new projects decided?

I'll start off by saying that I don't want to name a specific project that I have questions about. I might be misunderstanding this completely so I'll avoid creating a witch hunt.

So there's this new project and they're rolling out their newly dropped token. When I check several sources, there is an indication of max supply but no indication of circulating supply. The top 5 wallets own around 97% of the total supply at the moment. Yet this token is priced at almost $3 which would put their market cap on almost $3 billion while they released a couple of days ago. How does this work? Where does this value come from? Isn't it reasonable to assume that all projects start at $0 and they can gain value by people simply buying the tokens?

To me, it all seems extremely sketchy but it's also the first time I'm following a rollout from the start. Can anyone explain/clarify how something like this happens? It would be much appreciated. Thanks in advance!