What the DeMarker indicator shows
An oscillator is an indicator whose readings move within a defined scale. Both DeMarker versions in our platform use a 0–100 scale. Each value reflects the balance of two price components accumulated over a selected number of bars. It is not a percentage probability of a rise or decline.
The area above the upper band is conventionally called overbought; the area below the lower band is called oversold. These names describe the line’s state. Price can keep rising with a high reading or falling with a low one. Examine the price chart, the sequence of bars and the time spent outside the band.
DeMarker I vs DeMarker II
DeMarker I · changing extremes
The first version compares the current high and low with the previous bar’s high and low. It accumulates increases in highs and decreases in lows over the selected period, then compares the two components.
DeMarker II · the position of the close
The second version uses the current high and low relative to the previous close, together with the current close’s position within its bar. Identical periods therefore do not produce identical lines.
This describes the accepted SW implementation based on Thomas DeMark’s New Market Timing Techniques (1997). Other editions and services may use different variants or settings. Neither DeMarker I nor DeMarker II in this implementation uses volume.
One price chart, two different readings
Compare the lines vertically: a date refers to the same completed daily bar in every panel. The two versions receive identical quotes but compare different price components. Different values and crossing dates are expected rather than evidence of a fault.
Look for brief excursions outside 40–60 and for longer stays beyond a band. Compare those stretches with rising or falling price above. There are no entry arrows in this illustration: a crossing alone does not prescribe a trade.
DeMarker I and II settings in the platform
| Parameter | Default | What it controls |
|---|---|---|
| Period | 8 bars | The window over which price components accumulate. |
| Lower / upper band | 40 / 60 | Zone boundaries and the conditions for the Duration count. |
| SW Duration | 16 consecutive bars | The first consecutive bar eligible for highlighting outside a band. |
| Scale | 0–100; midpoint 50 | A shared scale for both versions. 50 is not a 50% probability. |
Set the period, bands and Duration threshold independently for each line in the indicator panel on the right. Period and Duration accept values from 1 to 250. The lower band must be below the upper band and both must stay within 0–100. A line and its Duration highlighting can be shown or hidden separately.
The period 14 and bands 30/70 found in some other descriptions are not this platform’s starting settings. Before comparing examples, check the version, period and bands. Changing a Sequential calculation preset does not change DeMarker settings.
SW Duration: how long the line stays beyond a band
Duration counts consecutive bars strictly above the upper band or strictly below the lower band. With the default threshold of 16, the first fifteen bars of that run remain unshaded. Highlighting begins on the sixteenth and continues while the condition holds. Earlier bars are not shaded retrospectively.
A return inside the bands, exact equality with a boundary or an unknown value ends the previous run. A move directly to the opposite side starts a new count at one. Duration 16 on a weekly chart means sixteen weekly bars; on a monthly chart it means sixteen monthly bars, rather than a fixed sixteen calendar days.
A long stay outside the bands identifies a persistent indicator state. The count does not predict a reversal date. Editing the Duration threshold changes the start of highlighting while leaving the DeMarker line itself unchanged.
Open and read DeMarker on your own chart
Load history
Choose a symbol and Day, Week or Month, then press Load. The platform uses a snapshot of completed bars; load it again to refresh the history.
Enable one version
Select SW DeMarker I or SW DeMarker II in the right indicator panel. Its line appears below price. For a comparison, enable the second version and keep the settings identical.
Compare the line with price
Locate a move beyond a band, examine its duration and follow subsequent completed price bars. A high or low reading alone does not confirm a reversal.
Save the workspace
Save the indicator selection and parameters. Each of the two charts has its own selection; choose the relevant chart before editing its settings.
If history is too short for a complete calculation window, or a value cannot be determined, the line has a gap. An unknown value is not replaced by zero or the midpoint and does not continue the Duration run. These two indicators do not require volume.
DeMarker and Sequential answer different questions
Sequential and Combo label stages of a price sequence with 9 and 13 on the main chart. DeMarker I and II provide a continuous reading in a separate panel. DeMarker is therefore not another count to thirteen.
When using them together, first understand each study independently. A 13 appearing near a DeMarker excursion gives you two observations; that coincidence alone does not specify a probability, entry price or acceptable loss.
Questions before you begin
What is the default DeMarker period?
SW DeMarker I and II start with period 8, bands 40/60 and Duration 16. These are the defaults of the chosen implementation; each line can be configured independently.
Is DeMarker II an improved DeMarker I?
It measures different price components and produces a different line. Its version number does not establish more accurate forecasts or better performance.
Do DeMarker I and II need volume?
No. The accepted platform calculations for both versions use price data.
Does a reading above 60 mean I should sell?
The reading alone does not. It can remain above the band while price keeps rising. Compare it with Duration and actual price behaviour.
Why is part of the line missing?
The calculation needs a full window of known observations. Insufficient history or an undefined value produces a gap rather than an invented zero.
About these examples
This article’s illustration was prepared on 16 October 2026 using the accepted SW DeMarker I and II calculations and the MSFT history snapshot saved on 13 October 2026. The visible window is 20 May–20 August 2024; calculations include the preceding loaded history. It is an original explanatory chart, not a customer account screenshot or a strategy performance test.
STUDENT WYCKOFF is an independent platform inspired by Tom DeMark’s publicly published work. These explanations describe the SW implementation on this site, not an official DeMark service.
Implementation reference: Thomas R. DeMark, New Market Timing Techniques (1997), DeMarker I and II and Basic Settings chapters. The platform uses its selected 1997 settings rather than mixing defaults from different editions.