I would assume most people are buying something else at the same time they are selling, so it would be mostly a wash.
That's not really how real estate prices work.
Around here, people don't like to move in the rainy season. For a fixed number of houses that are for sale at any given moment, you'll find lots more buyers in the spring than you will in the winter. Some of them are moving up the ladder from rentals, and some (okay lots) are moving here from other parts of the country. Some are just
new people, born and raised here and now working and looking to live somewhere, but the supply of houses is significantly restricted.
This is essentially why the Seattle prices are so crazy. There just aren't very many single family homes in Seattle, and yet the city is growing by tens of thousands of people per year. Tens of thousands of new bedrooms and kitchens and parking spaces need to be built for them, and they can't built anywhere near that many SFRs so people end up forced into apartments or condos and competition is fierce for properties with updated kitchens, central locations, big yards and gardens, free parking and garages, and the other amenities that people in the suburbs typically take for granted when shopping for a new house.