OHLC candles summarize the open, high, low and close over a defined period. They describe price movement while discarding much of the sequence of trades. Learn what the body and wicks measure, then keep execution and future-price claims separate from the information actually retained.
The body occupies one-third of the range, while the open-to-close return is 5%. These measure different things.
BTKWIN.COM · EDUCATIONAL EXAMPLEIdentify the price series behind the four letters
O means open, H high, L low and C close. In standard trade-based candles, these summarize recorded prices during the source’s window. Record pair, venue, product and timeframe before using them. A BTC/USD spot candle does not automatically describe a perpetual contract or an aggregated index.
The TradingView candle explanation describes bodies between open and close and wicks extending toward high and low. Color settings can also compare with the previous close rather than the current open. Read the actual values when viewing unfamiliar settings.
A close does not necessarily mean the market stopped trading. In a continuous market it is the value completing that candle window. The rightmost ongoing candle instead has a provisional displayed close that can change. Mark completion status before comparing examples or documenting a signal.
Calculate the body, wicks and full range
Assume a hypothetical completed candle opens at 100, reaches 110, falls to 95 and closes at 105. Body length is the absolute difference between open and close: five. The upper wick is 110 minus the greater of open and close, also five. The lower wick is the lesser of open and close minus 95, again five.
Full range is high minus low, or fifteen. Open-to-close change is (105 − 100) ÷ 100 × 100 = 5%. Body divided by range is 5 ÷ 15, approximately 33.33%. The latter describes candle shape, not the asset’s return over the period.
| Hypothetical measurement | Calculation | Result |
|---|---|---|
| Body | Absolute value of 105 − 100 | 5 |
| Upper wick | 110 − max(100,105) | 5 |
| Lower wick | min(100,105) − 95 | 5 |
| Range | 110 − 95 | 15 |
| Open-to-close return | (105 − 100) / 100 | 5% |
Reverse open and close to 105 and 100 while keeping the high and low unchanged. Body length remains five, but return becomes approximately −4.76% because its starting base is 105. Equal absolute distances do not produce symmetric percentage gains and losses.
OHLC cannot reconstruct the order of every move
One hypothetical path is 100, then 110, then 95, then 105. Another is 100, then 95, then 110, then 105. Both yield the same four OHLC values. The candle alone cannot tell you which extreme happened first, regardless of how clear its final shape looks.
For a position already open before the window, a target at 109 and stop at 96 encounter different sequences in those two paths. A historical test using only the candle must not choose whichever sequence produces the most favorable result. It needs finer data or an explicit rule for unresolved intrabar order.
Even a level appearing within the candle does not guarantee your order filled there. Trigger reference, bids versus asks, queue priority and available quantity can affect execution. An OHLC summary does not record your queue position or prove that sufficient opposing size existed for every waiting order.
An ongoing candle is not its final historical record
Suppose an early snapshot shows open 100, high 106, low 99 and current price 104. Later the price visits 95 and 110 before the window ends at 105. The earlier snapshot was a valid observation at its time, but it was not the final candle.
If a study requires a completed close, record that requirement and use the information available when the period actually ends. Intraperiod monitoring can also be legitimate when identified as such. The problem is treating final high, low and close as though they were all already known near the beginning.
Keep capture time and bar boundaries with screenshots. The daily-candle comparison guide explains why timezone boundaries and market identity can change which trades belong to the period.
A candle-shaped display can use transformed prices
The TradingView Heikin Ashi guide explains a calculated chart using averaged values to smooth movement. Its familiar body-and-wick shape should not be mistaken for a direct record of all executable prices.
Likewise, last-trade, mark and index series can each be summarized as OHLC. The letters describe the summary operation rather than identifying the underlying series. Save chart type and price reference alongside pair and timeframe before comparing two bodies or investigating an apparent data error.
Check internal consistency and the imported columns
For a standard valid candle, high should be at least as large as open and close, low should be no greater than them and low should not exceed high. A failed check calls for reviewing field order, units, transformation and source quality rather than immediately using the row in calculations.
An API row can include timestamps, volume, trade count and other fields around the prices. Do not assume a universal order from memory. Read its documentation or file header and compare a known row with the chart. Decimal and thousands separators also need the correct interpretation.
To combine complete smaller candles, take the first open, maximum high, minimum low and final close after sorting chronologically. Do not average opens or sum highs. Confirm that the periods exactly cover the desired window without duplicates or unexplained gaps. Valid individual rows do not establish complete coverage.
Describe the observation without inventing a cause
A long upper wick shows a measured distance from the upper body to the high. It does not identify who sold or why. A small body also does not establish the direction of the next candle. Separate a description such as close near open after a wide range from any proposed explanation.
Additional volume or order-book data can answer other questions only when market, time and units align. Whole-market daily volume cannot automatically explain a five-minute local candle. Base-asset and quote-currency volumes are also different numerical measures.
Use a reproducible practice exercise
Choose a completed candle, record its source and four prices, then calculate body, both wicks, range and open-to-close change. Body plus upper and lower wicks should equal range within rounding. If range is zero, body-to-range division is undefined, so record that condition instead of forcing a percentage.
Save the result in the watchlist notes with the actual market and timestamps. The exercise establishes what the candle contains and what remains unknown. Execution history and future outcomes require additional evidence beyond its four numbers.
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English content and examples reviewed: 27 October 2026. Read the Arabic edition.
