> If you're borrowing money using a mortgage in order to invest in stocks, that's probably not particularly smart. If you have both a mortgage and investments,

> If you're borrowing money using a mortgage in order to invest in stocks, that's probably not particularly smart. If you have both a mortgage and investments, that is almost literally exactly what you’re doing. If your mortgage is below a 4% rate, this is almost certainly a great idea. If it’s above that, it may be a reasonable approach (up to a point). I have a mortgage at 2.375% and I can assure you I intend to pay it off over the full 30 year duration. Every early payment is an enormous opportunity cost compared to leaving it in the markets over the remaining duration.