Renko Charts: Bricks That Filter the Noise
Renko charts are built from bricks: fixed-size blocks that print only when price travels the full brick distance, and ignore everything smaller. A renko chart has no wicks, no time axis, and no memory of the moves that never completed a brick. What survives on the screen is the part of the move that actually went somewhere, which is why the chart reads as a cleaner trend than the candles underneath it ever showed.
The brick size gives the chart its character. A two-point brick on an index ignores every two-point wobble; a ten-point brick ignores everything smaller than a real leg. Choose the size and you have chosen what counts as movement. That choice is not cosmetic: it decides how many trades the chart can even describe, and a brick size smaller than the instrument's normal noise produces a chart full of flips that filter nothing.
How a Brick Forms
The rules are mechanical. Price starts a brick at a level, and nothing prints until price closes one full brick beyond it. A rise of one brick size prints a rising brick; a fall of one brick size prints a falling brick. Most renko implementations add a reversal rule: before a brick prints in the opposite direction, price must travel two brick sizes against the current column, one to break even and one to turn. The reversal rule is the filter's teeth, because a one-brick pullback inside a trend prints nothing at all.
Time disappears as a side effect. A column can take five minutes or three weeks to build, and the chart does not care. Two charts of the same instrument can show completely different renko histories purely because the brick sizes differ. The x-axis is brick count, and the y-axis is price. Everything else was filtered out on purpose.
The trend read follows directly. Consecutive bricks of one color climbing at roughly forty-five degrees is the chart's version of a trend, and it is deliberately hard to argue with: every brick on it represents a completed move of the full brick size. The first opposite brick, which by the reversal rule took a double move to print, is the trend's first real objection. Traders who use renko for direction treat that first counter-column the way candle traders treat a structure break: as the read's invalidation, not as a signal to reverse blindly.
What the Filter Hides
The honesty section matters more on renko than on most charts. Bricks hide three things by design. They hide the path: a column of rising bricks says price crossed each level, not how violently, and a ten-point brick printed on a smooth drive looks identical to one printed on a spike. They hide gaps: an overnight gap of thirty points may print as a few ordinary bricks stacked in sequence. And they hide timing entirely, which means renko cannot show a trader when anything happened, only in what order.
Execution inherits those costs. A stop that "sits below the last brick" sits below an averaged construction, and the real low beneath that brick may be a full brick lower. The renko chart decides direction; the real chart decides prices. The pairing is the same discipline as the averaged-candle lesson: read the trend on the filtered chart, place the orders on the true one.
One blunt rule: renko does not predict, it records. A column of rising bricks is a record that price has been paying up. Nothing in the construction promises it will keep doing so, and the reversal rule exists precisely because the answer eventually becomes no.
A Worked Example: Three Points of Nothing
The following numbers are invented for illustration, a hypothetical instrument with a two-point brick and a standard two-brick reversal.
The instrument rallies from 100 to 110. The chart prints five rising bricks: 100 to 102, 102 to 104, 104 to 106, 106 to 108, and 108 to 110. The current column stands at five bricks, and the chart is a clean staircase.
Then price pulls back to 107. Three points against the trend, a move that on a candle chart prints a visible red candle or two. On the renko chart, nothing prints. A falling brick requires price to reach 108 minus nothing: the reversal rule needs two brick sizes, so the first falling brick prints only below 106, at 105.99 or lower. The pullback to 107 never got there, so the chart still shows five green bricks and no objection at all. The noise was not smoothed; it was never admitted.
Only if price keeps going, through 106 and then to 105.99, does the first falling brick print, down at 106 to 104. By then the pullback has proven itself: it moved four points against the trend, twice the brick size, and the chart says so with one brick. A deeper fall to 103 prints a second falling brick. The table below is the lesson in four rows.
| Price move | Size against trend | What renko printed |
|---|---|---|
| Rally 100 to 110 | With the trend | Five rising bricks |
| Pullback to 107 | 3 points | Nothing: below the reversal threshold |
| Fall to 105.99 | 4 points | First falling brick, 106 to 104 |
| Extension to 103 | 7 points | Second falling brick, 104 to 102 |
The invalidation on this chart is mechanical and visible: the first falling brick is the trend's objection, and a second confirms that the objection had weight. A trader who treats the brick size as the trend's definition never has to argue with the chart about whether a pullback mattered. The chart already answered, in its own currency, which is completed movement.
Choosing the Brick and Using the Chart
Brick selection is a working decision, not a setting to fiddle with. The practical method is to match the brick to the move being traded: a swing trader studying weeks of an index might use a brick the size of an average daily range fraction, while an intraday trader uses one sized to the session's legs. Two checks validate a choice. The chart should print few enough bricks that the trend columns are readable at a glance, and enough that the reversals arrive while they are still tradeable rather than after the move is over.
A practical sizing habit ties the brick to volatility: measure the instrument's average daily movement, then pick a brick near one quarter to one third of it, and check the result against the two tests above. Instruments change regime, and a brick tuned in a quiet month prints too much noise in a trending one, so revisit the setting when the character of the tape shifts. Renko is not a set-and-forget chart; it is a filter that needs its threshold matched to the market it is filtering. Renko pairs naturally with the tools from this block. The market's pools and levels are found on the real chart, then watched on the renko chart for the trend's verdict: a level that produces a stack of reversal bricks was defended by real flow. The kill-zone windows say when the verdicts tend to arrive. What renko adds is the calmest possible picture of the result.
The next lesson removes another axis: a chart with no time and no averaging, where price marks itself in X's and O's one box at a time.
Renko Chart Questions
How big should the brick size be?
Large enough that ordinary noise cannot print, small enough that real legs still do. A working check: the brick should filter most intraday wobbles while printing several times inside the move being traded. If every pullback prints a reversal column, the brick is too small for the instrument.
Why did a big move print fewer bricks than expected?
Because bricks count completed traversals, not distance in a straight line. A move that gaps, chops, and retraces inside one brick's span may cross the same ground repeatedly without closing a full brick beyond any level, and renko records none of the repetition.
Can stops be placed on renko levels?
No. A brick edge is a construction line, not a traded price, and the real move behind a brick may have ranged well beyond it. Read direction on the renko chart, then place entries and stops on the real chart's actual prices.
Does renko work on every instrument?
It works wherever price moves in legs larger than the noise, which suits indices, futures, and liquid currency pairs. Thin instruments with jumpy, gap-prone tape produce misleading columns, because the bricks record jumps as if they were walks.
Renko filters by movement size. The next chart filters by something stricter still: it records only price levels that were actually reversed from, one box at a time, and throws away both time and volume.