You can use it for different things. my main use for it is to project targets based on impuls legs. not always will an ABCD pattern have the AB=CD 1:1 ratio. CD will often be in a fib ratio to AB like indicated on the chart. using the tool you can find different levels quickly and even set your own custom level values.
You can find it in your drawing toolbar by...
S&P 500 comparison to VXO (implied volatility of OEX options) -- former VIX -- during the stock market crash of October 1987.
What caused the crash of 1987?
According to a 2006 Federal Reserve paper, a combination of circumstances made the crash possible. In the five years preceding the crash, stocks were supported by new entrants into the market (pension and...