OHLCV stands for Open, High, Low, Close, and Volume. It is the standard format for representing aggregated price data over a defined time period, whether that period is one minute, one hour, one day, or any other interval. Each OHLCV bar (also called a candlestick) summarizes all trading activity within that period into five values, making it the most widely used data format in technical analysis and backtesting.
What each component represents
The Open is the first traded price at the start of the time period. The High is the highest price reached during the period. The Low is the lowest price reached during the period. The Close is the last traded price at the end of the period. Volume is the total number of shares or contracts traded during the period.
Together, these five values capture the price range and trading activity for each period. The relationship between Open and Close indicates the direction of the move (bullish if Close is above Open, bearish if below). The High and Low define the total range and show how far the price extended beyond the Open and Close.
OHLCV versus tick data
OHLCV data is an aggregation of underlying tick data. A single 1-minute bar might summarize hundreds of individual trades into five numbers. This compression reduces data volume dramatically and makes analysis more manageable, but it also discards information. Within a bar, the sequence of price movements is lost. A bar with a High of $101 and a Low of $99 does not reveal whether the price went to $101 first and then $99, or vice versa.
This information loss affects backtesting accuracy. If a strategy has both a stop-loss and a profit target that fall within the same bar's range, it is impossible to determine which was hit first without sub-bar data. Tick-level data resolves this ambiguity by providing the exact sequence of prices.
Common time frames
Daily bars are the most common for swing trading and long-term strategy analysis. Intraday bars (1-minute, 5-minute, 15-minute) are used for day trading strategies. Weekly and monthly bars are used for longer-term analysis. The choice of time frame should match the strategy's holding period and signal frequency.
Lower time frames provide more data points but also more noise. A pattern that appears significant on a daily chart might be invisible on a 1-minute chart due to the higher noise-to-signal ratio at shorter intervals.
Data quality considerations
OHLCV data quality varies by provider. Key issues include adjusted versus unadjusted prices (split and dividend adjustments), extended hours versus regular hours data, and handling of gaps between trading sessions. For backtesting, it is important to use consistently adjusted data and to understand whether the provider's bars include pre-market and after-hours trading.
Practical example
A 5-minute bar for a stock might read: Open $100.00, High $100.50, Low $99.80, Close $100.30, Volume 15,000. This tells us the bar opened at $100, reached as high as $100.50, dipped as low as $99.80, and closed at $100.30 on 15,000 shares of volume. A strategy using this data can calculate indicators like moving averages, RSI, and Bollinger Bands from the Close prices, and use Volume for volume-based indicators.
How Tektii helps
Tektii supports both OHLCV bar data and tick-level data for backtesting. Strategies can consume data at any resolution, from daily bars for longer-term approaches to raw tick data for intraday strategies. The platform handles data aggregation and storage efficiently so traders can choose the resolution that matches their strategy's requirements without worrying about data infrastructure.