I think it's legitimate
Based on what? Do you have any evidence or proof of payouts?
They do have investment plans for btc, but I think you'd have to be on the lunatic fringe to deposit a coin that valuable on yobit so as to earn money with it.
So what you are saying is if you deposit anything with actual value, it is likely to get stolen? So in what way is this "legitimate"?
There is no investment program in the world which can promise returns of 10% a day whilst also claiming to be "100% safe". This is a scam.