Gap and Go vs. Gap Fill: A Comparative Analysis
The Black Book of Day Trading Strategies
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Momentum trading thrives on identifying price moves that carry strength and direction early in the trading day. Two of the most significant gap-related setups are Gap and Go and Gap Fill strategies. Both approaches leverage the open’s price gap but focus on different price behaviors and trader psychology. Mastering when to use one versus the other, with specific rules and risk parameters, can sharpen your edge as a momentum trader.
This article breaks down these two strategies, providing you with real trade setups, technical parameters, and practical advice on when and how to apply each to your trading toolkit.
Understanding Gaps: The Foundation
A gap occurs when a stock’s opening price is materially different from its previous close, creating a “space” on the chart where no trading took place. Gaps are classified into several types, but the two we focus on here are:
- Gap and Go: Price gaps in one direction at the open and continues moving strongly in that direction, often triggered by significant news, earnings, or market sentiment.
- Gap Fill: Price gaps initially in one direction but then reverses to fill the gap by moving back toward the prior day’s close.
Both setups offer momentum opportunities, but they behave differently and require distinct strategies.
Core Concepts
1. Gap and Go
“Gap and Go” assumes that the market’s initial direction at the open will continue. Buyers (or sellers) dominate from the outset, showing strength immediately through volume and price action.
Key characteristics:
- Gap is at least 2% away from previous close.
- Volume on the gap-up or gap-down bar is 2x or more the average volume over the past 20 days.
- Price holds above (or below) the opening price with minimal retracement.
- Confirmation often comes through a break of the opening range.
2. Gap Fill
This strategy bets on a reversal to fill the open gap during the day. Price initially moves away from the previous close but then retraces to “fill” the gap area.
Key characteristics:
- Gap size is often smaller (0.5% to 2%), but larger gaps can fill later in the session.
- Early volume spike may fade, price loses momentum.
- Price revisits or crosses the previous day’s close, often resting around the mid-gap level.
- Traders use this setup to fade overextended moves.
Strategy 1: Gap and Go Setup
Use this when you see a large gap accompanied by strong pre-market news, and volume confirms strength.
Indicators and Settings:
- 20-period Exponential Moving Average (EMA20) on 5-minute chart.
- Volume: Compare current bar volume to 20-day average volume.
- Relative Strength Index (RSI) set to 14 with an emphasis on crossing above 60 for longs (below 40 for shorts).
- Opening Range: Use the first 5 minutes to set high and low.
Entry Rules:
- The stock gaps at least 2% above or below prior close on strong volume (e.g., 2x average).
- Wait for the first 5-minute bar to complete; identify the Opening Range High (ORH) and Opening Range Low (ORL).
- For gap-ups:
- Enter long on a break above ORH with volume confirming strength.
- For gap-downs:
- Enter short on a break below ORL with volume confirming strength.
- RSI(14) should be above 60 for longs, below 40 for shorts at entry.
Stop-Loss:
- Place initial stop-loss just below the opposite side of the opening range (ORL for longs, ORH for shorts).
- Alternatively, use 0.5% below the entry price for tighter risk control.
Target Price:
- Target 1: 2% above entry.
- Target 2: 3-4% above entry if volume and momentum persist.
- Use a trailing stop if the price accelerates past first target.
Example Table: Gap and Go Trade Metrics
| Metric | Value |
|---|---|
| Previous Close Price | $100 |
| Opening Price | $102.50 (2.5% gap-up) |
| Average Volume (20-day) | 500,000 shares |
| Opening Volume | 1,200,000 shares (2.4x average) |
| Opening Range (5-min) | High: $103.00, Low: $102.00 |
| RSI (14) at Entry | 65 |
| Entry Price | $103.05 (break ORH) |
| Stop-Loss | $102.00 (ORL) |
| Target 1 | $105.11 (+2%) |
| Target 2 | $107.21 (+4%) |
Trade Setup Walkthrough
- At market open, your stock gaps from $100 to $102.50 on high volume.
- After 5 minutes, opening range: high $103.00, low $102.00.
- RSI(14) reads 65.
- Price breaks above $103.00 with confirmed volume.
- Enter long at $103.05.
- Place stop-loss at $102.00.
- Take partial profit at $105.11.
- Let the remainder run to $107.21 or trail stop.
Strategy 2: Gap Fill Setup
Use this when the gap is smaller, volume fades after the open, or news sentiment isn't overwhelmingly strong.
Indicators and Settings:
- 20-period EMA on 5-minute chart to track intraday trend.
- Volume spike on open followed by declining volume bars.
- MACD (12, 26, 9) for bearish/bullish divergence.
- Check price relative to previous close (the gap level).
Entry Rules:
- The stock gaps up/down between 0.5% and 2%.
- After opening spike, volume decreases and momentum wanes.
- Price moves back toward the previous day’s close.
- Confirm with MACD histogram crossing zero (from positive to negative for gap-up fills, vice versa for gap-down fills).
- Enter short (for gap-up fills) or long (for gap-down fills) near the midpoint of the gap or the prior day’s close.
- Prefer entry when price crosses EMA20 against the opening direction.
Stop-Loss:
- Set stop just beyond the last swing high/low before the reversal.
- Alternatively, 0.5% away from entry for tighter management.
Target Price:
- Target filling the entire gap (previous day’s close).
- Partial profit target at midpoint of the gap.
- If momentum fades further, tighten stops and prepare to exit.
Example Table: Gap Fill Trade Metrics
| Metric | Value |
|---|---|
| Previous Close Price | $50 |
| Opening Price | $51.00 (2% gap up) |
| Volume Spike | 600,000 (3x average) |
| Current Volume | 200,000 (declining) |
| EMA20 (5-min) | $50.60 |
| MACD Histogram | Crossing from +0.05 to -0.02 |
| Entry Price | $50.65 (crossing EMA20 downward) |
| Stop-Loss | $51.05 (recent high) |
| Target 1 | $50.25 (gap midpoint) |
| Target 2 | $50.00 (previous close) |
Trade Setup Walkthrough
- Stock gaps from $50 to $51.00 on heavy volume.
- Initial volume spike fades as price stalls above $51.
- Price crosses below EMA20 (5-minute) to $50.65.
- MACD histogram crosses below zero.
- Enter short at $50.65.
- Stop-loss at $51.05.
- Take partial profit at $50.25.
- Hold remainder for full gap fill at $50.00.
Summary Table: Comparison of Gap and Go vs. Gap Fill
| Feature | Gap and Go | Gap Fill |
|---|---|---|
| Gap Size | ≥ 2% | 0.5% to 2% (can be larger) |
| Volume | Strong, sustained volume ≥ 2x avg | Initial spike then declining volume |
| Trend Indicator | Price breaks above/below Opening Range | Price crosses EMA20 against gap direction |
| Momentum Confirm | RSI(14) > 60 (long), <40 (short) | MACD histogram crosses zero |
| Entry Timing | Break of 5-min Opening Range | Retracement near prior day close or mid gap |
| Stop Loss | Opposite Opening Range boundary or 0.5% away | Beyond last swing high/low or 0.5% away |
| Target | 2% to 4% move in gap direction | Fill entire gap with partial at midpoint |
| Market Context | Strong, confirmed news or catalyst | Weak or fading momentum after gap |
Final Words: Practical Advice for Execution
-
Volume is important. Never trade gap strategies without confirming volume behavior. Gaps on low volume are usually not tradeable momentum.
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Use tight stops relative to the opening range or recent volatility. Gaps can be volatile; protecting your capital is essential.
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Watch pre-market and news flow. Gap and Go works best when clear catalysts drive the market; Gap Fill benefits from fading overextensions without strong news.
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Monitor intraday technical signals. Using EMA20 on 5-minute charts, RSI(14), and MACD can give objective cues for entry and exit.
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Develop a playbook based on your preferred style and backtest both setups over several months. Each stock behaves differently.
By distinguishing between these two gap-based momentum plays and applying specific rules with concrete parameters, you position yourself to profit in a wide range of market conditions. Your discipline in execution, focus on volume, and attention to intraday price action will determine your success in mastering Gap and Go and Gap Fill strategies.