Investing tenant’s security deposit

[Filip Reutov]

I don’t own any properties YET and am very new to the real estate world, but earlier I was reading Brandon Turner’s “The Book On Rental Property Investing” and it sparked an idea in my head about tenant security deposits. I was wondering what everyone’s opinion is on investing your tenants security deposit. Is it a good idea, is it legal, if so what avenue would you take if any, to invest that money?