Even though it might not be why you're buying or selling right now, but many people are choosing this time of year because they have school-age children.  If they're going to move, they want to get it done before the next school year starts.  The traditional fall through beginning of summer school year drives many folks to list and search.  It brings a lot more inventory on the market and in turn helps out folks who don't have kids, but are shopping just the same, as they now have more to choose from.