The Renko charting method is thought to have
acquired its name from "renga" which is the Japanese word for bricks.
Renko charts are similar to Three Line Break charts except that in a
Renko chart, a line (or "brick" as they're called) is drawn in the
direction of the prior move only if prices move by a minimum amount
(i.e., the box size). The bricks are always equal in size. For example,
in a 5-unit Renko chart, a 20-point rally is displayed as four, 5-unit
tall Renko bricks.
Kagi charts were first brought to the United States
by Steven Nison when he published the book, Beyond Candlesticks.
Interpretation
Basic trend reversals are signaled with the
emergence of a new white or black brick. A new white brick indicates the
beginning of a new up-trend. A new black brick indicates the beginning
of a new down-trend. Since the Renko chart is a trend following
technique, there are times when Renko charts produce whipsaws, giving
signals near the end of short-lived trends. However, the expectation
with a trend following technique is that it allows you to ride the major
portion of significant trends.
Since a Renko chart isolates the underlying price
trend by filtering out the minor price changes, Renko charts can also be
very helpful when determining support and resistance levels.
Example
The following charts show Intel as a classic
high-low-close bar chart and as a 2.5-unit Renko chart.
I drew "buy" and "sell" arrows on both charts when
trend reversals occurred in the Renko chart. You can see that although
the signals were late, they did ensure that you invested with the major
trend.
Calculation
Renko charts are always based on closing prices. You
specify a "box size" which determines the minimum price change to
display.
To draw Renko bricks, today's close is compared with
the high and low of the previous brick (white or black):
If the closing price rises above the top of the
previous brick by at least the box size, one or more white bricks are
drawn in new columns. The height of the bricks is always equal to the
box size.
If the closing price falls below the bottom of
the previous brick by at least the box size, one or more black bricks
are drawn in new columns. Again, the height of the bricks is always
equal to the box size.
If prices move more than the box size, but not
enough to create two bricks, only one brick is drawn. For example, in a
two-unit Renko chart, if the prices move from 100 to 103, only one white
brick is drawn from 100 to 102. The rest of the move, from 102 to 103,
is not shown on the Renko chart.