Because I think that long term the Market will certainly rebound. The (over) reaction around the world over the Brexit will correct itself. With the large drops witnessed on Friday, that certainly gives strong buying opportunities, or "discounted stocks". The Market will come back. I used Apple as an example because it dropped down to $93.40....it's 52 week high is almost $133. I think long term it's bound to start climbing up towards its high rather than keep dropping.
There are a lot of professionals that agree with that opinion.