as I rmb I heard of this before, but dunno is it just a scam...
is there any BTC wallet there will provide you interest?
There are wallets that generate interest but it is very small like under 6% a year so pretty much what a bank would give you but a bank would charge you bs fees. It is legit in the way it is a stable and doable investment and they let you know where the money comes from ot is totally legit. But !! The problem is you dont actually own your own coins when using an online wallet. You only truelly own them when you own the keys and wallet.DAT file so they could run one day. I'm not saying they will but you dont known that. I'm not sure what re coarse you could get if they ran.
Your bank gives you 6% interest annually? Please link me your bank, thats 5x as much as any bank i know. Are u sure about that? Also what has security to do with a service such as poloniex giving interest?