That makes me think of another question.....
Say you have a 400,000 mortgage on what was (when you bought it) a $500,000 house. So you put down the 20% ($100K) and now you are left with your $400k mortgage.
Now I doubt this would happen... but if something happend to the RE market and it got cut in half.. and your home was now worth only $250k and your mortgage was still $400k...
Could the bank then "call you" on that difference? Like how in the stock market they do margin calls? Tell you that you have 90 days to pay the $150k difference or they will have to terminate your mortgage?
That could be a big problem for homeowners.
