announce out, page-26

http://www.investopedia.com/articles/technical/02/042202.asp

it is best used to tell you when to enter or exit - and to my mind is best for people who prefer to wait for a confirmation before entering - or exiting

in other words when this fires a buy or sell the trend has already changed. If you enter earlier higher risk

If you are trying to pick the bottom to get in before a trend change you will need something else imho - as well as a strong stomach for risk