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Do you know about these types of portals, or can you provide more information on how and why they operate like this? Who is involved, and why are they selling Tether at these values?
Bro, the more hidden they are, the riskier it is for you, Bitcoin and other cryptocurrencies are plain in transactions even if they are decentralised, so the so-called hidden strategy or association is nonsense to me even as their transactions are obvious when they move money, so what? There is no big deal here and for you not to have found them through the search engine means that they are not popular. I do not think this should raise our curiosity for any reason but to forget them and follow the right/best procedures to own, hold and move your coins as you wish.
And please, be very careful about scams on the internet, I have seen similar packages like this where they use invitation to scam people even as they remain hidden when you search for them. But it was in fiat. Since it's USDT, what is the difference? They can come in divers ways. Be careful!
I personally won't be involved any investments that's sorounded in secrecy, and the more secret it is the more it's not likely to be genuine for me, and since the OP was not willing to give more information about the project, then how can the experienced members in this forum be able to understand better and offer advice. Let him just beware of being scammed, because I don't know how someone can be able to carry out research on something that's sorounded in secrecy. Let him just invest the amount that he can afford to loose, if he must engage in this hidden portal, so if it's a scam, the lose will not affect him much.