Opening Range Breakout (ORB)
Opening Range Breakout (ORB) marks the high and low of the first N minutes of the session and treats a close beyond either level as the day's directional trigger.
What it measures
ORB captures two prices per session: the highest high and the lowest low across the opening window (default 5–15 minutes). Those two levels become the day's reference — a breakout above the range is a long signal, a break below is a short signal.
Parameters
| Name | Default | Range | Note |
|---|---|---|---|
| range_minutes | 15 | 5–60 | 5m is aggressive (many breakouts, more failures); 30m and 60m produce fewer but higher-quality signals. |
| session_start | exchange open | exchange open, custom | Defaults to the primary session (09:30 ET for US equities). Custom sessions matter for FX and crypto. |
How it behaves
On trend days, price breaks the ORB early and does not look back — the range acts as one-sided support (or resistance) for the rest of the session. On rotation days, price prints outside the range briefly, fails, and reverses back through — the classic "false breakout" that fills the middle of the range.
When it misleads
ORB fails on low-volatility sessions where the opening range is unusually tight — a small ATR-relative range breaks in both directions before finding a real direction. It also fails right around scheduled news that lands during the opening window: the range is already the news reaction, and breaks beyond it are exhaustion, not initiation. Filter with an ATR floor and skip event opens.
Backtest result
Sourced backtest in preparation — we're running the rule on our own historical candles before publishing numbers we can stand behind.
FAQ
- What is the best ORB duration?
- 15 minutes is the most-cited default for US equities. Futures traders often go shorter (5m). The right answer depends on the instrument's typical intraday rhythm.
- ORB on 24/7 markets?
- Requires an arbitrary session anchor (UTC midnight, exchange handover, London open). ORB is native to session markets; on 24/7 instruments it works only if the anchor is one everyone else is watching.
- Do I need volume to confirm ORB?
- Not strictly, but a break with volume expansion has a much higher continuation rate than one on shrinking volume. Treat volume as a confidence filter, not a required input.
Build a strategy with ORB
Drop the block into the Nodlow builder and backtest on real historical data.
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