Yes I mean investment platforms like Coinbase, Kraken...
So if i understand well, I do not need to use several investment platforms to minimize the risk as long as I have a personnal wallet.
Coinbase don only have 2 coins which you can able to buy up which is Bitcoin and Etherium. For kraken its an exchange which you can have several lots of coins to be traded on.If you are looking forward on making it as a web wallet or storage of your bitcoins then risk is really there because anytime they can be hacked or shutdown. No one really knows this is why don't store up huge amounts on those platforms. If you are a trader just put up a significant amount that would be needed on your trade and also coinbase is not really literally an trading site since it do have only 2 coins.Its just good for buying up.