The housing bubble

Yep. It has happened before, it will happen again, it is happening now: new buyers simply cannot get into the market, and the housing market, like the stock market, consists of a smaller and smaller base bidding up their own wealth among each other.
At some point, the people at the top slow down or stop, and the ponzi game is over.
Stocks get properly valued, and so must houses. To paraphrase Tiny Tim, "and so must we all be properly valued, every one of us."
Australia has the dubious distinction of being the leader, with a 13% annualized decline in housing prices.