Open, High, Low, CloseOHLC
OHLC are the four prices recorded for each period on a chart: the first traded price (open), the highest (high), the lowest (low) and the last (close).
Every bar or candle on a chart is a summary of everything that happened in that period, squeezed into just four numbers. Learn those four and every chart becomes readable.
- Category
- Technical Analysis
- Reading time
- 3 min
- Also called
- OHLC bar, Price bar
- Updated
OHLC in plain words
Each Candlestick shows the high, low, open and close for the selected timeframe.1
On an OHLC bar, the top and bottom of the vertical line are the high and low.2
The open is a short tick to the left and the close a short tick to the right.1
How to read an OHLC bar
Find the high and low
The high and low mark the top and bottom of the bar.2
Find the open
The open is the short tick on the left.2
Find the close
The close is the short tick on the right.1
Compare open and close
On candles, the body shows open and close and the wicks show the extremes.1
Decide what matters
Some traders care most about the close, which is why line charts use closes only.2
Worked examples
Example 1 — Reading one bar
Up day, $4 rangeA hypothetical daily bar: open $50, high $53, low $49, close $52.
| Range | $53 − $49 = $4 |
| Change | +$2 |
The high and low mark the top and bottom of the bar, and the close tick sits right of the bar at $52.1
Example 2 — Down bar
Down day near the lowOpen $80, high $81, low $76, close $77.
| Change | −$3 |
| Close vs low | $1 above low |
On a candle, the body would span $80 to $77 and the wicks reach $81 and $76.1
Example 3 — Same data, line chart
Simpler but less detailFive daily closes: $10, $11, $10.5, $12, $12.5.
| Line chart uses | Closes only |
Line charts focus on the close and are used when open, high and low aren't available.2
OHLC bar vs candlestick
| Aspect | OHLC bar | Candlestick |
|---|---|---|
| Prices shown | All four | All four |
| Open shown as | Left tick | Body edge |
| Close shown as | Right tick | Body edge |
| Visual emphasis | Range | Body |
How traders use OHLC data
Measuring range
Using high minus low for Volatility tools such as Average True Range.
Spotting gaps
Comparing today's open with yesterday's close to find a Price Gap.
Pattern reading
Reading candle patterns built from OHLC.
Backtesting
Using OHLC history for Backtesting.
Advantages and disadvantages
Advantages
- Summarises each period in four numbers.
- Works for any market and timeframe.
- Basis for most indicators.
Disadvantages
- Hides the order in which high and low happened.
- Hides everything between the four prices.
- Bars can look cluttered on long charts.
- Open and close depend on session definitions.
Going deeper
Read as far as you need. Each level builds on the one before it.
Four prices
Beginner
Each candle shows the high, low, open and close of its period.1
Bars vs candles
Intermediate
Bar charts look very similar to candles; the open is a left tick instead of a body edge.1
Close-only views
Advanced
Some traders weight the close above the other three, and line charts are used when the rest is unavailable.2
Common mistakes
Mixing up the ticks
Reading the left tick as the close.
Assuming order
Thinking the high came before the low.
Ignoring session times
Different platforms start days at different hours.
Forgetting a live bar
Treating an unfinished bar as final.
Check your understanding
Test yourself before moving on. Each answer comes with an explanation.
Key points to remember
- OHLC = open, high, low, close.
- Bars use ticks; candles use bodies.
- Range = high − low.
- The order inside the bar is hidden.
- Most indicators are built on OHLC.
Frequently asked questions
Is a candlestick the same as OHLC?
What is the close of a live bar?
Why are colours different between platforms?
Further learning
- Candlestick
The most popular OHLC view.
- Trading Chart
Chart types compared.
- Average True Range
A range measure from OHLC.
- Price Gap
What open vs prior close reveals.
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.
- CMC Markets. Trading Charts: Learn to Read Price Charts (opens in a new tab) Checked .
- StockCharts ChartSchool. What Are Charts? (opens in a new tab) Checked .
Educational content, not financial advice. Examples use hypothetical prices and simplified costs; actual fees, margin rules and regulations vary by broker, market and country. We are not affiliated with any publisher linked above. Last reviewed . Report an error or request a source credit.