This all said, on a very long-term time frame, a person may want to start putting in buy levels during the next major dip. I mean, if someone is 0% invested, and they want to put a large sum to work, on the dips they should probably start going long to some degree. 20% invested, maybe at first until we're sure a bottom has hit. Just depends on their personal strategy.

I would just not conclude that I am seeing a bull market yet. It's a "wait and see" market, but people can still invest into those situations, especially with very long-term horizons.