Indicators are the most visible part of technical analysis — the coloured lines and panels that fill a trading screen. They are also the most misunderstood. An indicator is not a prediction and not a signal service. It is a formula applied to past prices that re-expresses them in a way that highlights one particular feature: direction, speed, volatility or average value.
Used well, a small set of indicators makes it easier to read a chart objectively. Used badly, a crowded screen of contradictory lines gives false confidence. This guide explains how the most widely used indicators are calculated, what each actually measures, how traders read them, and where each one tends to mislead.
How to think about indicators
Every indicator falls into one of a few families:
| Family | Indicators | Question it answers |
|---|---|---|
| Trend | Simple moving average (SMA), exponential moving average (EMA) | Which way is price heading, and how steeply? |
| Momentum | RSI, MACD, Stochastic | Is the recent move accelerating or fading? |
| Volatility | Bollinger Bands, Average True Range (ATR) | How much is price moving, regardless of direction? |
| Volume-weighted | VWAP | What is the average price, weighted by how much traded at each level? |
Two principles follow from this:
- Pick one indicator per question. RSI, Stochastic and MACD all describe momentum. Showing all three mostly repeats the same message.
- Indicators lag. Because they are calculated from past prices, they confirm what has already happened. That is useful — but it means they will always be late at turning points.
Throughout this guide, keep in mind the foundation from our technical analysis guide: price structure — trends, support and resistance — comes first, and indicators add context to it.
Moving averages
A moving average smooths price by averaging the closing prices over the last n periods and plotting that average as a line. As each new candle closes, the oldest one drops out — so the average "moves".
Simple moving average (SMA)
The SMA adds up the last n closes and divides by n. A 20-period SMA on a 1-hour chart is the average close of the last 20 hours. Every period in the window has equal weight.
Exponential moving average (EMA)
The EMA gives more weight to recent prices. Each new value is a blend of the latest close and the previous EMA, using a weighting factor of 2 ÷ (n + 1). For a 20-period EMA that factor is about 0.095, so the newest close contributes roughly 9.5% of the new value and the previous EMA the rest. The result reacts faster than an SMA of the same length.
How traders use moving averages
- Trend direction. Price above a rising moving average describes an uptrend; below a falling one, a downtrend.
- Dynamic support and resistance. In a steady trend, pullbacks often stall near a widely watched average such as the 20- or 50-period.
- Crossovers. When a faster average crosses above a slower one (for example 20 above 50), traders read it as momentum turning upward, and vice versa.
Where moving averages mislead
In a sideways market, price crosses back and forth over its moving averages and crossovers fire repeatedly in both directions, producing a string of small losses. Moving averages are trend tools; in ranges they mostly generate noise. Our trend-following strategy guide discusses how traders filter for trending conditions.
Relative Strength Index (RSI)
RSI was introduced by J. Welles Wilder in his 1978 book New Concepts in Technical Trading Systems. It compares the size of recent gains with the size of recent losses and scales the result between 0 and 100.
The standard setting uses 14 periods. Roughly: RSI = 100 − 100 ÷ (1 + average gain ÷ average loss). When gains have dominated recently, RSI is high; when losses have dominated, it is low.
Reading RSI
- Overbought and oversold. Readings above 70 are conventionally called overbought and below 30 oversold. These describe how one-sided recent movement has been — not that price must reverse.
- The 50 line. RSI holding above 50 suggests gains are outweighing losses; below 50, the opposite. Some traders use it as a simple momentum filter.
- Divergence. If price makes a higher high but RSI makes a lower high, upward momentum is weakening. Divergence is a warning, and it can persist for a long time before price turns.
Where RSI misleads
In a strong trend, RSI can stay "overbought" for weeks while price keeps climbing. Selling every time RSI crosses 70 in a bull trend means repeatedly trading against the dominant move. RSI's overbought and oversold levels work best in ranging markets.
MACD (Moving Average Convergence Divergence)
MACD was developed by Gerald Appel in the late 1970s. It measures the relationship between two exponential moving averages of price.
- MACD line: the 12-period EMA minus the 26-period EMA.
- Signal line: a 9-period EMA of the MACD line.
- Histogram: the difference between the MACD line and the signal line, drawn as bars.
Reading MACD
- Above or below zero. When the MACD line is above zero, the faster EMA is above the slower one — upward momentum. Below zero, downward momentum.
- Signal-line crossovers. The MACD line crossing above its signal line suggests momentum turning up; crossing below, turning down.
- Histogram shrinking. A shrinking histogram shows momentum fading even while the MACD line is still positive or negative.
Where MACD misleads
MACD is built from moving averages, so it shares their lag and their weakness in ranges. Crossovers in a flat market are frequent and mostly meaningless.
Bollinger Bands
Bollinger Bands were created by John Bollinger in the 1980s. They consist of three lines:
- Middle band: a 20-period simple moving average.
- Upper band: the middle band plus two standard deviations of price over the same 20 periods.
- Lower band: the middle band minus two standard deviations.
Because standard deviation measures how spread out recent prices are, the bands widen when volatility rises and narrow when it falls.
Reading Bollinger Bands
- The squeeze. When the bands contract to an unusually narrow width, volatility is low. Periods of low volatility tend to be followed by periods of higher volatility — though the bands do not tell you which direction the expansion will take.
- Walking the band. In strong trends, price can ride along the upper (or lower) band for many candles. A touch of the upper band is not by itself a sell signal.
- Mean reversion in ranges. In sideways markets, moves to the outer bands often fade back towards the middle band.
John Bollinger's own guidance stresses that the bands describe relative highs and lows, not automatic buy or sell signals, and that they work best combined with other tools.
Average True Range (ATR)
ATR, also introduced by Wilder in 1978, measures volatility. For each candle it takes the true range — the largest of: high minus low, the gap between the high and the previous close, or the gap between the low and the previous close. ATR is the average of these true ranges, typically over 14 periods.
ATR has no direction. A rising ATR means candles are getting bigger; a falling ATR means they are getting smaller.
How traders use ATR
ATR is one of the most practical indicators because it feeds directly into risk management:
- Stop-loss distance. A stop placed 1.5 × ATR beyond a support level adapts automatically to current volatility — wider in turbulent markets, tighter in calm ones.
- Position size. A wider stop means a smaller position for the same money at risk. Our risk management guide shows the calculation.
- Realistic targets. If a market's daily ATR is 80 points, expecting a 400-point move in one session is unrealistic.
Stochastic oscillator
The Stochastic oscillator, developed by George Lane in the 1950s, compares the latest close with the range of prices over a lookback period (commonly 14). It is expressed as %K, with a smoothed line, %D, plotted alongside.
- %K near 100 means price closed near the top of its recent range; near 0, near the bottom.
- Readings above 80 are conventionally called overbought and below 20 oversold.
- %K crossing %D is read as a short-term momentum shift.
Like RSI, the Stochastic works best in ranges and can stay at extremes for long periods during trends.
VWAP (Volume-Weighted Average Price)
VWAP is the average price weighted by volume: price levels where more was traded count more. It is usually calculated from the start of a session and resets each session.
Institutions often use VWAP as a benchmark for execution quality — buying below VWAP is considered a good fill for that session. Short-term traders watch it as an intraday reference: price holding above VWAP suggests buyers have been in control during the session.
VWAP depends on volume data. For over-the-counter instruments, volume reflects activity on the venue providing the price rather than the entire market, so treat VWAP there as an approximate guide.
Combining indicators sensibly
A clean, complementary setup might look like this:
| Purpose | Choice | Why |
|---|---|---|
| Trend context | 50-period SMA | Objective description of direction |
| Momentum | RSI 14 | Shows whether moves are strengthening or fading |
| Risk sizing | ATR 14 | Sets stop distance to current volatility |
Each tool answers a different question, and none of them repeats another. Contrast this with RSI, Stochastic and MACD on the same chart — three ways of asking the same momentum question.
A worked example
On a 4-hour chart of Ethereum, price is above a rising 50-period SMA (uptrend context). It pulls back to a support zone, and RSI dips from 65 to 45 without falling below 40 — the pullback has cooled momentum without breaking it. ATR is 60. A trader planning a long entry might place the stop-loss 1.5 × ATR (90) below the support zone, and size the position so that a 90-point loss equals 1% of the account.
The indicators do not say that Ethereum will rise. They describe the trend, confirm the pullback was orderly rather than a collapse, and set the stop at a distance that reflects how much Ethereum is currently moving.
Common indicator mistakes
- Using default settings without understanding them. RSI 14 and MACD 12/26/9 are conventions, not optimal values. Know what changing them does.
- Optimising settings to fit the past. Tweaking parameters until a backtest looks perfect usually produces a system that fails on new data — a problem covered in how to test a trading strategy.
- Treating overbought as "sell". In trends, extremes persist.
- Ignoring price. If the indicator says one thing and clear price structure says another, price is the primary evidence.
Indicators on RumiEX
The RumiEX chart includes SMA 20, SMA 50, EMA 20, Bollinger Bands and VWAP as overlays on the price chart, alongside readouts for RSI, MACD, ATR and the Stochastic oscillator. Indicator lines update as the current candle forms, and the charting tools guide explains how to turn them on and combine them with drawing tools.
Key takeaways
- Indicators re-express past price data; they lag and do not predict.
- Group indicators by family — trend, momentum, volatility, volume-weighted — and use one from each family you need.
- RSI and Stochastic extremes work best in ranges; moving averages and MACD work best in trends.
- ATR is one of the most useful indicators because it ties stop-loss distance and position size to real volatility.
- Price structure comes first; indicators add context.
Practise reading these indicators on live prices in a free demo account, or continue with chart timeframes and multi-timeframe analysis.
Frequently asked questions
What is the best technical indicator?
There is no single best indicator. Each measures one aspect of price — trend, momentum, volatility or volume-weighted value. The useful question is which aspect matters for your strategy, and then choosing one indicator that measures it clearly.
Does RSI above 70 mean I should sell?
No. RSI above 70 means recent gains have been large relative to recent losses. In strong uptrends RSI can stay above 70 for long periods while price keeps rising. Overbought and oversold readings are more useful in ranging markets, and as warnings rather than signals.
What is the difference between a simple and an exponential moving average?
A simple moving average gives every period in the window equal weight. An exponential moving average gives more weight to recent prices, so it reacts faster to new moves but also produces more false signals in choppy markets.
How many indicators should I use?
Usually two or three at most, from different families — for example one trend tool and one momentum or volatility tool. Several indicators of the same type mostly repeat the same information and can create false confidence.
Do indicators work on all timeframes?
The formulas work on any timeframe because they use whatever candles you give them. Default settings such as RSI 14 were designed with daily data in mind, so on very short timeframes they react to smaller, noisier moves.
Sources and further reading
- New Concepts in Technical Trading Systems — J. Welles Wilder Jr., Trend Research (1978)
- Bollinger Bands — John Bollinger, BollingerBands.com
- Technical Analysis: Power Tools for Active Investors — Gerald Appel, FT Press (2005)
Written and reviewed by the RumiEX Editorial Team. This article is for education only and is not financial, investment or tax advice. Read our editorial standards.