The S&P 500 is currently at 2772. On Jan 3, 2016 when this was posted it was at 1922. It is currently up 44% from when this prediction was made.
If we drop 30% today you'll still have more money than you did on Jan 3, 2016, and buying back in if you went to cash will be more expensive than if you'd bought on Jan 3, 2016.
Just a few numbers I found interesting. This might be a good one to reference when the next doom and gloom warning post comes up.