Following our discussion of lognormal distributions:

Find a large-cap stock that's been around for at least 15 years. Using F\# or
Matlab or R or anything you want, compute the daily fractional changes for the
period 1995-2005.  Plot these using a histogram; Is their distribution normal,
lognormal, or neither? Draw a Q-Q plot to see whether either is a good match.

Then, do the same for the period 2005-2010.  Again: what does the distribution
look like? Draw both the distribution histogram and the Q-Q plot.