Average Directional Index
Average Directional Index or ADX is a technical indicator, originally developed by J. Welles Wilder, that can be used to judge the strength of a trend in a given market.
ADX uses a combination of the Directional Movement Indicators (DMI) in addition to a moving average trend line.
When the ADX line moves above 30, the current trend is deemed to have strength, if the ADX is below 20 the market is deemed to be trendless or to have a very weak trend.
If the current ADX value indicates that a trend is weak, this doesn't always mean the price isn't moving. It could also signal a change in direction. It is also possible that the market is too volatile for a clear trend to be determined.
Relative Strength Index
Relative Strength Index or RSI is a technical indicator, originally developed by J. Welles Wilder, that is used to measure momentum and the magnitude of price changes in a given market. RSI can be used to identify whether a market is overbought or oversold.
If the current RSI is over 70 it is usually interpreted as a sign that the market is currently overbought (or over valued) and that a trend reversal or correction may occur soon. If the RSI is below 30 then it is usually interpreted as the market being oversold (or undervalued) and again, a reversal may occur soon.
Directional Movement Index
Directional Movement Indicator or DMI is a technical indicator, originally developed by J. Welles Wilder, that is used to identify the direction in which a market may be moving as well as the strength of that direction. DMI is usually used in conjunction with other indicators in order to reduce the number of 'false signals'.
DMI consists of two indicators. DMI positive (DMI+, green on the DMI chart above) and DMI negative (DMI-, purple on the DMI chart above). If DMI+ is higher in the chart than DMI- this signifies that the market direction is up. If DMI- is over DMI+ this signifies that the market movement is down.
Additionally, the further apart the two values are, the strong the directional movement is deemed to be. Finally, the point at which the lines cross is generally used by traders as a signal (in conjunction with other indicators) to buy or sell.