Any reason to not use leverage to buy more S&P 500?

I'm using TD direct investing the annual interest rate for leveraged capital is 4.75%, the average annual appreciation for the S&P 500 is about 10.5%. There are definitely more fruitful places to put my money, but as a no risk investment is there any reason for me not to leverage my S&P 500 shares for more S&P 500 shares?