Not crazy at all but definitely comes with major risks as many have pointed out.
A little different version is in my case I had cash from the sale of some family land and instead of paying off my 2% mortgage, I chose to put it all in the market.
Similar thought process - put into a broad US market ETF and let it earn 7/10% while I continue to pay off the 2% mortgage like normal.
Hopefully, it all works out - I guess for me the key is long term - I can pay the mortgage no matter what happens AND I do not need the money for 10+ years.
7/10%, that's part of the trouble isn't it? With "published" inflation rates ~ 8.5% ( I expect more increases as the fed "fights" inflation) plus long term capital gains tax of 15%, you have to get 9.8% just to break even. If you take short term gains the tax rate is your top rate for income tax purposes.
On the other hand, my house is appreciating considerably faster than our income. So your home equity is probably on the rise pretty strongly.
For most people in the US today, their net worth (median) IS the equity in their home.
