Think of it as a lever.  More cash investment up front equals more cash flow.  It is really as simple as that.  Everyone WANTS no cash investment and lots of cash flow.  Sorry….   That’s why KKR and alot of the Merger & Acquisition deals of the late 80s failed.  They overpaid for a company and saddled it with too much debt AND at too high an interest rate.  The whole thing is bound to fail.  Same thing goes for real estate.  Don’t plan on putting no money down AND not having a cash cushion.   Anyone who “sells” you anything else is giving very bad advice.  If you put 50% down on a real estate investment, then you don’t need a cash cushion because your Principal and Interest payment are low relative to your net operating rental cash flow.  If you put nothing down, more than likely, you have negative cash flow which can normally be more than offset by your income tax savings.   Sound complicated?  it is, and isn’t.  Just talk to a knowledgable and experienced professional like an accountant and they can explain how all this ties together.