Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

How to invest 100k
How to spend the money is up to you. That includes spending money on your house. (This is a safer way to look at it than an "investment". Not that it can't ever be treated as such, but that doing so often makes it easy to justify bad decisions and overspending on the house.) So with regards to the mortgage: So if it's not a monstrously huge deal, you might prefer to avoid default. Now,  how to invest the rest while waiting to spend it, now...