> Having understood that, the effective yearly simple interest rate on my particular Robinhood margin (extra buying power) is only 5%/year so all I have to do i

> Having understood that, the effective yearly simple interest rate on my particular Robinhood margin (extra buying power) is only 5%/year so all I have to do is earn higher than a 6% return each year. If you are planning to use margin, I dearly hope you don't use Robin Hood. You can get much cheaper margin loan from other brokerages like Interactive Brokers (less than half as much).