As I write this on Wednesday, December 19th the stock market has closed down 351.98 points or nearly 1.5% to its lowest level of the year, according to CNBC. The broader S&P 500 Index also closed at a 2018 low. But as bad as this news is, perhaps even more concerning are two key indicators for the housing market – single-family housing starts and homebuilder sentiment – both of which showed disappointing results.