Renko is a type of chart developed by the Japanese that is only concerned with price movement; That is to say time and volume are not included.
It is thought to be named for the Japanese word for bricks, "renga".
A Renko chart is constructed by placing a brick in the next column once the price surpasses the top or bottom of the previous brick by a predefined amount.
White/ Green bricks are used when the direction of the trend is up, while Black / Red bricks are used when the trend is down.
This type of chart is very effective for traders to identify key support/resistance levels.
Transaction signals are generated when the direction of the trend changes and the bricks alternate colours.