Implied volatility is one of the most tried and true methods for objectively
measuring expected volatility in the spot market. Derived from currency
options with different maturities, implied volatilities are used to help predict
potential movements in the spot market and is one of the most popular strategies
of systems traders and other professional hedge funds.
At its most fundamental, the basic and intuitive interpretation of this
implied data is often the most telling for traders. Taken alone, a steady
rise in the longer-term implied volatility (the red
line) is indicative of a strengthening trend; while inversely, a decline
often reveals that a period of range or consolidation in spot is ahead or
already in place. Additionally, the histogram or spread between the
shorter and longer-term implied volatilities (the blue
colored bars) tells a different perspective. As the histogram rises,
volatility is expected to pick up faster in the near future relative to the
longer-term range. Ultimately, this increases the probability of a
breakout scenario in the underlying currency. 

