Let’s say you plan to buy a house in 12-18 months. You have the money for a down payment, but it’s in the market right now (combo of ETFs and individual stocks). 

Do you:
(1) Keep the money in the market but in a more conservative portfolio 
(2) Put the money in a savings account and sit on it
(3) Something else

In the same boat, I have the money to buy it in cash, but I'll be loaning money still from the bank and keeping money in the markets (1). 

Reason for this to leverage loan money as good debt, since I can chip in bit by bit from my portfolio, not miss out on gains, and have cash to invest elsewhere when opportunity arises