The graph is wrong, @300 days are missing, or should it be 8 July 1931?Simon.
The concluding date 8 July 1932 on the legend is the date the post 1929 decline of the Dow Jones reached its bottom and is the concluding point of the black line. The horizontal axis shows the number of trading days since the peak and therefore the red line extends for 363 days - the number of trading days since the peak on 9 Oct 2007. The 1929 decline continued for 713 trading days before it reached its bottom.
Thanks John. As your stats will probably show, I'm a regular visitor to your very interesting blog. I hope it's OK by you that I often reference it and do my tiny bit to spread some of the news you help to translate for the rest of us non-economists.