Every Indian trader has stared at a gap-up open and wondered: chase it or fade it? Buy the gap or sell into it? The answer depends on what kind of gap it is.
Most retail accounts lose money on gaps because they treat them as one category. They aren’t.
The four kinds of opening gaps
- Common gap — small (< 0.3%), no real news. Fills almost always.
- Breakaway gap — opens past a recent consolidation high/low, driven by news or earnings. Usually continues.
- Continuation gap — happens mid-trend; the trend extends.
- Exhaustion gap — happens at the end of a trend; reverses.
Telling them apart in real time is the entire skill.
A simple decision tree
At 9:15, look at the open price relative to yesterday’s close:
- Gap size < 0.3% → ignore the gap; trade normally. Likely a common gap.
- Gap size 0.3% – 1.0% + no news → fade (gap-fill probability is high).
- Gap size 0.3% – 1.0% + clear positive/negative news → go with the gap after 15-min confirmation. Likely breakaway.
- Gap size > 1.0% → wait. The first 15 minutes will tell you which type.
The “wait” is the most underrated trade.
Gap-and-go (with the gap)
Conditions:
- Gap > 0.5% on actual news (results beat, large order win, sector tailwind).
- First 5-min candle holds above the open (for a gap-up).
- Volume in the first 5-min ≥ 2× average.
Entry: break of the 15-min high (this is essentially the ORB strategy). Stop: 15-min low or 1.2 × ATR, whichever is tighter. Target: project the gap distance up from the breakout.
Gap-fill (against the gap)
Conditions:
- Gap is between 0.3% – 1.0% with no clear catalyst.
- First 5-min candle prints lower wick / lower close (for a gap-up).
- Index is not gapping in the same direction (relative weakness).
Entry: break of the 5-min candle low. Stop: above the day’s high so far + small ATR buffer. Target: previous day’s close (full gap fill) OR VWAP.
Why pre-market matters
The pre-open session (9:00 – 9:15) gives you the “indicative open” — the call-auction price. Track:
- Indicative open vs yesterday’s close → gap size.
- Indicative open vs SGX Nifty → market context.
- Asian markets and US futures → global tone.
If the gap is fully explained by global cues, treat it as common. If it’s stock-specific, treat it as breakaway candidate.
Gap rules for earnings days
Earnings gaps are different — they’re driven by surprise, not by overnight news flow.
- Don’t trade the first 15 minutes. Spreads are huge.
- Look for the first sustained move post-9:30. That’s your direction.
- Use a wider stop (2 × ATR minimum). Earnings volatility eats normal stops.
- Take half-position size.
Sector gaps
Sometimes the whole sector gaps (e.g., banking gaps up after RBI policy, IT gaps down on USD strength). In this case:
- The strongest stock in the sector usually leads.
- The weakest stock will reverse first.
- Lead → continuation gap. Laggard → exhaustion gap.
Risk management on gap days
- Smaller position size. Volatility is higher; your stop distance widens; sizing must shrink to keep risk constant. Revisit stop-loss strategies.
- Tighter time stop. If your gap thesis isn’t working in 30 minutes, exit.
- Don’t average. Gaps that go against you tend to keep going.
Common mistakes
- Chasing the first 1-min candle. You’re trading noise, not signal.
- Fading every gap. Strong news gaps don’t fill; they trend.
- Ignoring the index. A gap-up stock against a gap-down index has poor odds.
- No volume check. A 1% gap on no volume is a future fade.
FAQs
Do all gaps fill? No. Common gaps usually fill same-day. Breakaway and continuation gaps may not fill for weeks.
Is gap trading better than ORB? They overlap. Most “gap-and-go” trades are essentially ORB with extra context. Pick one mental model and stick to it.
Best stocks for gap trading? Liquid Nifty 100 names. Avoid small-caps — gaps there are spread artefacts, not signal.
For the broader timing framework, see the best time to trade intraday on NSE.