Of course it would be best if one could buy low and sell high and pocket the change. But for a family with bunch of kids, it might be more important to have the space and stability. Even after selling a house, a family needs a equivalent place to live in; perhaps for rich families, the hassle isn’t worth a few 100K. For singles and couples who smartly bought back in 2000, I agree they should have sold last year and sit on the side line for few years.