According to that article prices are log normal. I experimented by plotting Bollinger bands on the log(price) and got exactly the same number of band crossings as when I plotted the usual bollinger bands. My sample was small, a 30 price average on one issue.
Did I overlook something? It looks like, preliminarily at least, that for trading purposes, standard Bollinger bands would hardly be less useful than the "real deal".
