That sounds similar to the interest rates on credit cards so chances are you'd be better off paying off all your credit cards first before going for it even if by some miracle it does turn out not to be a ponzi or outright scam...
What would be the chances?
Of it not being a ponzi I am not sure, usually ponzi claim much higher interest rates than that.
But usually they are promoted in the earn from home or internet marketing etc niches rather than the crypto niche, for crypto folk it is maybe about as high as they feel they can claim without being too obviously a scam.
I could easily see making way more than 25% in a year trading crypto, heck at small enough scales even the 1% a day ponzis often like to claim is do-able but scaling such things up is problematic, typically the more wealth you need to try to make a profit on the harder it is to get high returns, plus if you are making high returns what-for do you need "other people's money", you can make plenty by yourself and basically hog to yourself all the volume of profit any given profit-centre you come up with can yield.
Not to mention but here I go mentioning it anyway yikes USDT, fergoshsakes fiat is seemingly both designed and intended to
lose value over time, if fiat can offer 25% per year probably its because it intends to have that much inflation, that is, to lose that much value per year! I didn't know inflation was that bad yet but maybe so, even in the U.S. I am pretty sure a carton of cigarettes is no longer $2.70 nor a gallon of gas 27 cents and so on and so on. A lot of electronics might manage to get cheaper in fiat price but overall real things seem to show us that fiat loses value awfully darn fast...
So at the least if falling for some such scam pick one denominated in something that isn't itself in the first place by-design a losing proposition!
-MarkM-