DeMarker Oscillator: Complete Guide to Thomas DeMark's Indicator
The DeMarker oscillator is a powerful technical analysis tool developed by Thomas DeMark to measure the intensity of price changes. It helps identify overbought and oversold conditions, spot divergences, and predict trend reversals. In this guide we will cover the calculation formula, signal interpretation, and practical trading strategies.
1. What is the DeMarker Oscillator?
The DeMarker oscillator (Demarker Indicator) is a technical indicator developed by renowned trader and analyst Thomas DeMark. It is designed to measure the intensity of price changes over a given period. The core idea of DeMarker is to identify moments when the market becomes either overbought or oversold, which often precedes a trend reversal. Unlike many other oscillators (e.g., RSI), DeMarker focuses solely on closing price and does not use volume, making it more resilient to market noise.
DeMarker is a relative indicator, meaning its values depend on previous price data rather than absolute price values. This allows it to be applied to any financial market: stocks, currencies, cryptocurrencies, commodities. The indicator is particularly effective on daily and four‑hour timeframes, although it can be used on smaller periods with appropriate adjustments.
«DeMarker is not just another oscillator. It is a tool that looks at price dynamics from a unique perspective, comparing current highs and lows with previous ones. Its main strength lies in its ability to warn of reversals long before they become obvious.»
2. DeMarker Calculation Formula
DeMarker is calculated in several steps. First, two auxiliary values are computed: DeMax and DeMin.
- DeMaxi = Highi − Highi-1, if Highi > Highi-1, otherwise 0.
- DeMini = Lowi-1 − Lowi, if Lowi < Lowi-1, otherwise 0.
Then, for a chosen period N (standard N = 14), the sums of DeMax and DeMin over the last N periods are calculated. The DeMarker oscillator itself is calculated as:
where:
- Highi — current bar's high;
- Highi-1 — previous bar's high;
- Lowi — current bar's low;
- Lowi-1 — previous bar's low;
- N — number of periods (usually 14).
The resulting DeMarker value always lies between 0 and 1. The closer the value to 1, the stronger the buying pressure; the closer to 0, the stronger the selling pressure. Values of 0.7 and above are traditionally considered overbought, while 0.3 and below are considered oversold. However, these levels can be adapted to specific assets and timeframes.
3. Interpreting DeMarker Values
Classic interpretation of DeMarker is based on the 0.7 and 0.3 levels:
- DeMarker > 0.7 — overbought zone. Price is rising too fast, a correction or downward reversal is likely.
- DeMarker < 0.3 — oversold zone. Price is falling too fast, a bounce or upward reversal is likely.
- DeMarker between 0.3 and 0.7 — neutral zone, the market is balanced.
However, in a strong trend, DeMarker can stay above 0.7 (in an uptrend) or below 0.3 (in a downtrend) for a long time. Therefore, reversal signals should be confirmed by other methods (divergences, support/resistance levels, candlestick patterns). Many traders use stricter levels, such as 0.8/0.2, to filter out false signals.
Also important is the dynamics of the indicator: if DeMarker reaches an extreme and starts to turn without waiting to exit the zone, it can be an early signal. For example, if DeMarker rises to 0.75 and then starts to decline — it is a sell signal, even though it is still above 0.7.
4. Advantages and Disadvantages of DeMarker
✅ Advantages
- Easy to interpret — clear overbought/oversold levels.
- Versatility — works on any market and timeframe.
- Noise resistant — uses comparison of highs and lows, smoothing random spikes.
- Effective divergence detection — discrepancies with price give reliable reversal signals.
- No volume data required — available even on markets where volume is not published.
❌ Disadvantages
- Lag — like all oscillators, DeMarker gives signals with some delay.
- False signals in flat markets — frequent crossings of 0.7/0.3 levels in sideways markets.
- Does not show trend direction — requires combination with trend indicators.
- Sensitivity to period choice — standard period 14 is not suitable for all assets.
To minimise drawbacks, experienced traders use DeMarker in combination with moving averages, support/resistance levels, and higher‑timeframe filters.
5. Trading Strategies with DeMarker
Let us consider several proven strategies.
5.1. Strategy on crossing the 0.7 and 0.3 levels
Buy: when DeMarker falls below 0.3 and then rises above 0.3 (exit from oversold zone). Sell: when DeMarker rises above 0.7 and then falls below 0.7 (exit from overbought zone). Entry is made on the close of the candle that confirms the exit from the zone. Stop‑loss: beyond the nearest local extreme. Target: previous support/resistance level or 2-3 ATR. Important: in a strong trend, DeMarker can stay above 0.7 or below 0.3 for a long time, so the exit signal may be premature. It is recommended to use a trend filter (e.g., price above 200 EMA for buys, below for sells).
5.2. Divergence strategy
Divergence between price and DeMarker is one of the most reliable reversal signals. Bullish divergence: price makes a new low, while DeMarker makes a higher low. Buy signal. Bearish divergence: price makes a new high, while DeMarker makes a lower high. Sell signal. Entry is made after DeMarker turns from the second extreme. Stop‑loss beyond the price extreme. Target — previous level or 1-2 ATR. Divergences on DeMarker are especially strong on higher timeframes (H4, D1).
5.3. Combining DeMarker with moving averages
Determine the long‑term trend using EMA 200. In an uptrend (price above EMA 200), use only buy signals from DeMarker (exit from 0.3 or bullish divergence). In a downtrend (price below EMA 200), use only sell signals (exit from 0.7 or bearish divergence). This filters out false signals against the main trend.
5.4. Combining DeMarker with RSI
Using two oscillators increases reliability. A signal is considered strong when both indicators show overbought/oversold and divergence. For example, if RSI is below 30 and DeMarker is below 0.3 — the oversold zone is confirmed. If both then turn up — a buy signal.
«DeMarker is not a panacea, but in the hands of an experienced trader it becomes a sharp tool. Its divergences are especially valuable, often appearing several candles before a reversal.»
6. Divergences on DeMarker: How to Find and Use Them
Divergences are discrepancies between the direction of price movement and the direction of the oscillator. DeMarker is particularly sensitive to divergences, and they often precede strong reversals.
- Classic bullish divergence: price forms two consecutive lows, the second lower than the first, while DeMarker forms two lows, the second higher than the first. This indicates weakening bearish pressure. Buy signal.
- Classic bearish divergence: price forms two consecutive highs (the second higher than the first), while DeMarker forms two highs (the second lower than the first). Weakening bullish pressure — sell signal.
- Hidden divergence: used for trend continuation. Bullish hidden divergence — price makes a higher low, while DeMarker makes a lower low (signal to continue growth). Bearish hidden divergence — price makes a lower high, while DeMarker makes a higher high (signal to continue decline).
Practical Tips for Using DeMarker
- Choose the period according to your timeframe. For intraday trading (M5, M15) use period 9-14, for daily charts — 14-21, for weekly — 21-34.
- Do not use DeMarker in isolation. Always combine with trend indicators (moving averages, ADX) and levels.
- Backtest your strategies. Before applying DeMarker in real trading, test its effectiveness on historical data.
- Watch the news. Before important events, DeMarker may give false signals due to increased volatility.
- Use DeMarker to confirm breakouts. If price breaks an important level and DeMarker confirms the move (e.g., exits the oversold zone on an upward breakout), the signal is stronger.
How Technology Enhances DeMarker Analysis
Manual search for divergences and overbought/oversold levels on DeMarker takes a lot of time. Modern services like AemmTrader automatically calculate DeMarker on all timeframes, mark divergences and issue signals when crossing the 0.7/0.3 levels. The platform also integrates DeMarker into multi‑indicator strategies, e.g., combining with RSI and Stochastic to filter false signals.
Using such tools, you can focus on strategy rather than tedious calculations. This is the bridge between amateur and professional approaches — saving time and increasing efficiency.