Technical Indicator
A technical indicator is a calculation based on price, volume or both, plotted on or beneath a chart, that summarises some aspect of market behaviour.
A chart full of candles can be hard to read. A technical indicator runs those prices through a formula and draws the result as a line, giving you one clear reading — trend, momentum or volume — instead of hundreds of bars.
- Category
- Indicators and Tools
- Reading time
- 4 min
- Also called
- Trading indicator, Chart indicator, Indicator
- Updated
Indicators in plain words
Indicators are mathematical calculations plotted as lines on a price chart.1 In other words, they filter price action with formulas.2
Some use only closing prices; others also use Volume or Open Interest.2
A Moving Average is a simple example: it combines prices over a set period and divides by the number of data points.1
How to use an indicator, step by step
Pick what you want to measure
Decide whether you need trend, momentum or volume information; indicators help identify signals and trends.1
Know its inputs
Check whether it uses closing prices only or also volume and open interest.2
Check leading or lagging
Leading indicators try to forecast moves, while lagging ones look at past trends.1
Place it on the chart
Some indicators sit on top of price for direct comparison; others go in a separate panel.2
Set the period
Choose the lookback window, such as the number of bars in a moving average.1
Confirm with price
Treat the reading as a filter of price, not a replacement for it.2
Worked examples
Example 1 — A 5-day average
5-day MA = 11.4Closing prices over five days: 10, 11, 12, 11, 13.
| Sum | 10+11+12+11+13 = 57 |
| Average | 57 ÷ 5 = 11.4 |
A moving average adds prices over a period and divides by the number of data points.1
Example 2 — Overlay vs panel
Two views of the same pricesYou add a moving average and an RSI to a chart.
| Moving average | drawn over the price bars |
| RSI | drawn in a panel below |
Some indicators sit directly on the price chart for easy comparison.2 RSI, a popular leading indicator, usually gets its own panel below.2
Example 3 — Lag in action
Indicator trails pricePrice jumps from 10 to 15 in one day after four days at 10.
| Latest price | 15 |
| 5-day average | (10×4+15) ÷ 5 = 11 |
The average still reads 11 because it looks back at past prices, which is what makes it a lagging indicator.1
Common indicator types
| Aspect | What it measures | Example |
|---|---|---|
| Trend | Direction over time | Moving average |
| Momentum | Speed of price change | RSI |
| Volatility | Size of price swings | Bollinger Bands |
| Volume | Trading activity | Volume-based indicators |
How traders use indicators
Identifying trend
Using a moving average to judge the Trend.
Timing entries
Using momentum tools such as MACD in a Trade Setup and Entry Trigger.
Spotting divergence
Comparing indicator and price for Divergence.
Building rules
Turning readings into clear conditions in a Trading Strategy.
Advantages and disadvantages
Advantages
- Turn many prices into one readable line.
- Make rules objective and testable.
- Work on any market and timeframe.
Disadvantages
- Built from past prices, so they can lag.
- Different settings give different signals.
- Can give false signals in choppy markets.
- Stacking many indicators often repeats the same information.
Going deeper
Read as far as you need. Each level builds on the one before it.
A formula on price
Beginner
An indicator is a calculation plotted on the chart that helps identify signals and trends.1
Leading and lagging
Intermediate
Leading indicators try to anticipate price moves; lagging ones confirm trends after they start.1 See Leading and Lagging Indicators.
Inputs shape output
Advanced
Because indicators may use closing prices alone or add volume and open interest, two indicators on the same chart can disagree.2 Test settings with Backtesting before relying on them.
Common mistakes
Indicator overload
Putting five indicators on a chart that all measure momentum.
Ignoring price
Trading a signal that price action contradicts.
Over-tuning settings
Tweaking periods until they fit the past perfectly.
Expecting prediction
Treating a lagging tool as a forecast.
Check your understanding
Test yourself before moving on. Each answer comes with an explanation.
Key points to remember
- Indicators are formulas applied to price and sometimes volume.
- They are drawn on the chart or in a panel below.
- Leading tools try to anticipate; lagging tools confirm.
- Settings change the signals.
- Use them to filter price, not replace it.
Frequently asked questions
What is the best indicator?
How many indicators should I use?
Do indicators predict the future?
Further learning
- Moving Average
The simplest trend indicator.
- Relative Strength Index
A popular momentum oscillator.
- Leading and Lagging Indicators
How indicator timing differs.
- Backtesting
Testing indicator rules on past data.
Sources
This article is written in our own words. The sources below support the specific facts, rules and figures marked with a number in the text. Links open the original publisher’s page.
- IG. Top 10 Trading Indicators Every Trader Should Know (opens in a new tab) Checked .
- StockCharts ChartSchool. Introduction to Technical Indicators and Oscillators (opens in a new tab) Checked .
Read more elsewhere
- Trading Metrics (our sister site): Trading Indicators (opens in a new tab)
Educational content, not financial advice. Examples use hypothetical prices and simplified costs; actual fees, margin rules and regulations vary by broker, market and country. Trading Metrics is our sister site, under the same ownership; we are not affiliated with any other publisher linked above. Last reviewed . Report an error or request a source credit.