This article considers why housing market conditions, including the ratio of buyers to sellers, expected time-to-sale and transaction prices are sensitive to fundamentals. These high sensitivities result from feedback: market participants optimally respond to shocks in a manner that amplifies a shock's initial impact, which in turn elicits further reinforcing responses. For example, a positive demand shock brings more buyers into a market. This improves the bargaining position of sellers, who then sell more quickly, decreasing the stock of sellers in the market. This further increases the relative number of buyers to sellers, amplifying the initial shock.