I 'discovered' Williams %r when I was first starting out with AIM back in 1999. It is one af very many Technical Analysis measures one could use to help in the Buy Sell decision making process if you're a trader.
When I was trying to learn about TA, I had found the Technical Analysis from A to Z publication by Steven B. Achelis.
I see that he's since publiched a few versions of his books on the subject, but here is a link to a free on line version.
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