Yahoo! Finance - plotting trendline?

Question

After I export the Historical stock data as .csv and open it with Excel, I create a graph with a trendline.

Historical data example:

http://finance.yahoo.com/q/hp?s=EBAY&a=00&b=2&c=2003&d=08&e=21&f=2007&g=m

When I add a linear trendline and show the formula for the trendline, I see "y = 0.7892x + 21.336".

This appears to indicate a slope of 78%.

BUT the finance data is by MONTH. What is the annual percent gain?

Answer 1

If I understand your question (and a little clarification would help)

Can you annualize the data by averaging the results of 12 consecutive, fiscal or calendar months together and then plotting them?

That or plot 12 calendar months for a larger trend line.

BTW Ebay is up again today so far.