Low-Down Mortgages
  
Low-down mortgages are, shockingly, mortgages that require little or no down payment from the buyer in order to get the loan.
Standard mortgages usually require 20% of the requested loan or more as a down payment. For many buyers, that pretty much makes the whole idea of home ownership a no-go. These mortgages, such as an FHA loan, require less down (for example, just 3.5% of the requested sum).
In some cases, as with a rural development loan, the buyer might not be required to make a down payment at all. These are often marketed to first time buyers, or those with good credit and rental history, but not a great savings account.
Isn't that where "getting the low-down on something" came from? Eh. Maybe not.