STO is a new HYIP, which very soon goes out like IEO because in general its just projects that today have nothing good. It's all the same ICO, you just lose nothing, except as an opportunity to raise funds for the project.
Why do you think that STO is HYIP, I think it is different, because the projects are called STO need a lot of conditions.
we will know the results later whether the STO is HYIP or not, so in my opinion if we don't like the STO project then we don't need to join and if we like it then just go ahead.
all you have to make sure is that the project is fraudulent or not.