Click on graph for larger image in new window.The first graph is from Doug Short of dshort.com (financial planner): "Four Bad Bears".
Note that the Great Depression crash is based on the DOW; the three others are for the S&P 500.
This graph shows the seasonal pattern for the Case-Shiller Composite 10 house price index. The percentage change is the month-to-month change annualized.
It is important to remember this clear seasonal pattern when looking at the Case-Shiller data.