[jjeaff]

I'm afraid your logic is a bit flawed here. The home value increase or decrease does not factor in when considering your mortgage. Your mortgage continues to exist no matter where your home value goes.

You have to pay that same mortgage even if the market tanks and your home becomes worthless. Even in the case of just "letting it go" the bank will take your worthless house and will still come after you for what remains on the mortgage.

That is why putting money into your mortgage is a "risk free" investment at 4% (or whatever your rate is).