Can I take out a loan and pay off my mortgage?

That is a great idea! Think about it, If the economy slips and you cannot make mortgage payments you could lose your home. If you take out a stock loan and pay off your mortgage, you cannot lose your home. The reason is that this is a non-recourse loan the lender can only go after the pledged stocks, nothing else. Should you decide to stop making payments on the loan you will lose the stock, but if the economy, sudnnly turns chances are the stock may not be worth enough to keep paying the loan anyway.