Assuming "the big one" is constantly just around the corner is a really bad investment strategy. Just look at the pure statistics of it, the US stock market finishes the year positive over 74% of the time. You're playing a losing game trying to time it.

I know many of us are still emotionally scarred from the last credit crisis...but storing cash under your mattress is the wrong way to respond to those feelings. It was dumb when my grandparents did it 80 years ago after the Great Depression, and it is still dumb in 2019.

Of course, the world is uncertain and could end tomorrow. If you're uncomfortable with that idea, perhaps try religion?