Andrews Median Lines

Sometimes the geometry of markets just amazes me. Here is an example of the Andrews median line method. Notice how the Green median line, made using the secondary top late last year and the low in January, overlays (perfectly) exactly the more recent blue median line? Why is that?

Anyway here is another trick. If you put a link to the url that has your data on the chart, you can simply click on it to fetch more data.  In the lower left, that string of text is the following:

http://ichart.finance.yahoo.com/table.csv?s=%5EGSPC&a=04&b=21&c=2007&d=10&e=21&f=2008&g=d&ignore=.csv

Notice that I edited the last month to read October (and its only July). That way every time I click on that link I get Yahoo!'s most recent data. Its still manual (as apposed to automation) but it makes it very easy to update.