Definition
Open is the first observed price, high the maximum, low the minimum, and close the final price in the interval under the data provider’s rules. OHLC is commonly used to build bars and candles. It does not include trading volume unless an additional volume field is provided.
How It Works
For a hypothetical series of trades at 100, 104, 98, and 102, OHLC is 100, 104, 98, 102. The range is 6, while the close-to-open change is 2. Higher-timeframe OHLC takes the first open, highest high, lowest low, and final close of its component intervals; it does not average them.
Key Considerations
OHLC hides the path between observations and cannot reveal every transaction. Empty intervals, timezone boundaries, and different price sources may produce different records. An unfinished interval’s close is provisional, so comparisons should use consistent definitions and completed periods.