Interestingly, the last few pages of the TA A-Z doc cover both Williams %R and ZIG-ZAG...
A few Excerpts:
WILLIAM'S % R
Overview
Williams %R (pronounced "percent R") is a momentum indicator that measures
overbought/oversold levels. Williams %R was developed by Larry Williams....
...An interesting phenomena of the %R indicator is its uncanny ability to anticipate a
reversal in the underlying security's price. The indicator almost always forms a peak and
turns down a few days before the security's price peaks and turns down. Likewise, %R
usually creates a trough and turns up a few days before the security's price turns up.
ZIG ZAG
Overview
The Zig Zag indicator filters out changes in an underlying plot (e.g., a security's price or
another indicator) that are less than a specified amount. The Zig Zag indicator only shows
significant changes....
...The Zig Zag indicator is used primarily to help you see changes by punctuating the most
significant reversals.
It is very important to understand that the last "leg" displayed in a Zig Zag chart can
change based on changes in the underlying plot (e.g., prices). This is the only indicator in
this book where a change in the security's price can change a previous value of the
indicator. Since the Zig Zag indicator can adjust its values based on subsequent changes
in the underlying plot, it has perfect hindsight into what prices have done. Please don't try
to create a trading system based on the Zig Zag indicator--its hindsight is much better
than its foresight!
Be careful out there!
Best Regards, Steve (The Grabber)
