TradingView has become the go-to platform for traders and developers who want to create custom indicators, strategies, and automated trading systems. At the heart of this functionality lies Pine Script, a powerful domain-specific language designed specifically for financial analysis on TradingView.
One of the most essential yet often misunderstood features in Pine Script is the security() function. This function allows you to fetch data from different symbols or timeframes — a critical capability when building advanced multi-timeframe strategies or cross-asset indicators.
In this comprehensive guide, we’ll dive deep into the key parameters of the security function: lookahead, gaps, and how to correctly retrieve lower timeframe data within higher timeframe scripts. Whether you're backtesting a swing trading strategy or designing a real-time alert system, understanding these settings can prevent repainting and ensure your logic behaves as expected in live markets.
Understanding the Basics of the Security Function
The security() function enables Pine Script users to request price, volume, or indicator data from any symbol or timeframe available on TradingView. Its basic syntax looks like this:
security(syminfo.tickerid, "D", close)This line fetches the closing price of the current symbol on the daily chart, even if your script is running on a 1-hour chart.
However, without proper configuration, using security() can lead to repainting — where historical values change as new bars form — which invalidates backtests and misleads traders.
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Key Parameter 1: lookahead — Controlling Future Data Access
The lookahead parameter determines whether the security() call can access future data (i.e., data not yet confirmed at the close of a bar).
Syntax:
security(symbol, timeframe, expression, lookahead=barmerge.lookahead_on|off)lookahead=barmerge.lookahead_on(default): Allows access to the current incomplete bar's data. This may cause repainting because values update with each tick.lookahead=barmerge.lookahead_off: Restricts access to only fully closed bars. Prevents repainting and ensures integrity in backtesting.
Best Practice:
Always set lookahead=barmerge.lookahead_off when developing strategies meant for live trading or accurate historical testing.
Example:
dailyClose = request.security(syminfo.tickerid, "D", close, lookahead=barmerge.lookahead_off)This ensures that only confirmed daily closes are used — no peeking into ongoing price action.
Key Parameter 2: gaps — Handling Missing Data Periods
Markets don’t trade 24/7. For stocks, futures, or indices, there are regular gaps between sessions. The gaps parameter controls how security() handles these discontinuities.
Options:
gaps=barmerge.gaps_on: Fills missing periods withna(not available) values. Creates visible breaks in plots.gaps=barmerge.gaps_off(default): Extends the last known value forward until new data arrives.
When to Use Which?
- Use
gaps_offfor continuous visual indicators (e.g., moving averages across timeframes). - Use
gaps_onwhen you need to detect session boundaries or avoid false signals during market closes.
Example:
weeklyMA = request.security("AAPL", "W", ta.sma(close, 20), gaps=barmerge.gaps_on)This will show breaks in the weekly moving average during weekends — useful for strict session-based analysis.
Advanced Use Case: Fetching Smaller Timeframes on Larger Charts
A common challenge arises when trying to pull lower timeframe data (like 15-minute OHLC) onto a higher timeframe chart (like daily).
By default, security() aligns data based on closed bars. But if you're on a daily chart and want intraday granularity, you must handle aggregation carefully.
Solution: Use request.security_lower_tf()
This function retrieves multiple data points from a lower timeframe within a single higher timeframe bar.
intradayCloses = request.security_lower_tf(syminfo.tickerid, "15", close)This returns an array of 15-minute close prices that occurred during the current daily bar.
You can then analyze volatility, detect intraday patterns, or build volume-profile-like insights directly in Pine Script.
⚠️ Note: This function returns na if no lower TF data exists in the current bar (e.g., partial day), so always check for valid values before processing.
Avoiding Common Pitfalls in Multi-Timeframe Scripts
- Repainting Due to lookahead: Always disable lookahead unless explicitly needed for research purposes.
- Misinterpreting Gaps: Using
gaps_offmight smooth data but could generate misleading signals during non-trading hours. - Overloading with Lower TF Data:
request.security_lower_tf()can return large arrays — inefficient loops may slow down rendering.
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Frequently Asked Questions (FAQ)
Q: What does lookahead=barmerge.lookahead_off actually do?
A: It prevents your script from accessing data that isn't finalized on the source timeframe. This stops repainting by ensuring only closed bars are used in calculations.
Q: Can I use security() to get crypto data on stock charts?
A: Yes! You can reference any symbol available on TradingView. For example:
btcPrice = request.security("BINANCE:BTCUSDT", "D", close)Q: Why does my indicator repaint even with lookahead_off?
A: Check if you're using other functions that introduce forward-looking bias — such as ta.valuewhen, incorrect bar indexing, or plotting within unconfirmed conditions. Also verify all security() calls have lookahead disabled.
Q: Is request.security_lower_tf() suitable for real-time alerts?
A: Yes, but be cautious — it only returns data up to the last complete lower timeframe bar. During fast markets, there may be delays in full bar confirmation.
Q: How do I debug gaps in my multi-timeframe data?
A: Plot the fetched series with plot(na) checks and use bar_index markers to identify where data drops occur. Switching gaps=on can help visualize missing intervals.
Q: Can I combine multiple security calls efficiently?
A: Yes, but consolidate expressions where possible:
data = request.security(symbol, tf, [high, low, close])
[h, l, c] = dataThis reduces API overhead compared to three separate calls.
Final Thoughts: Building Reliable Strategies with Confidence
Mastering the security() function and its parameters isn’t just about syntax — it’s about building trust in your trading logic. With correct use of lookahead, gaps, and lower-timeframe requests, you can create robust systems that perform consistently across historical data and live execution.
Whether you're analyzing Bitcoin on multiple timeframes or building a session-based filter for forex pairs, these tools give you precise control over how data flows through your scripts.
As you continue refining your Pine Script skills, remember: clarity beats complexity. A simple, well-structured indicator with clean logic will outperform an over-engineered one every time.
👉 See how integrating multi-timeframe validation improves trade accuracy in live markets.