Hello. I see different platform like nexo, blockifi, etc... that can borrow you crypto or stablecoin. I'm here to ask if you have a strategy for example you borrow btc with an interest rate of 6% and then you use it on defi with 8% APR. Thanks for helpful. 
Borrowing money in order to invest is an advanced maneuver that should only be performed by expert traders, the reason for this is that you are taking an additional risk and as such it should only be done when all the factors align themselves and tell you that you have a very high chance of making money with such trade, if you do something like this when you are still a newbie thinking you can multiply your profits this way then you will lose all your capital in a heartbeat.