An inside bar is a classic two-candle contraction formation that indicates market consolidation. It occurs when a secondary candlestick trades entirely within the high-to-low price range of the primary candlestick (the "mother bar").
On the left, the current bar's high and low sit entirely inside the prior bar's range. On the right, one wick past the prior high is enough to disqualify it. Bodies and candle color do not matter.
Range vs. Body Mechanics
In technical analysis, traders distinguish between a candlestick's body (|Close − Open|) and its total range (High − Low).
Mother Bar Range = [Lowt−1, Hight−1]
Inside Bar Range = [Lowt, Hight]
Full Range Required: The inside bar test evaluates wicks (highs and lows) only.
Body Neutral: The opening price, closing price, and candle color (green or red) of either bar have zero bearing on whether the pattern qualifies.
Contrast with Engulfing Patterns: While engulfing patterns ignore wicks to evaluate body coverage, inside bars ignore bodies to evaluate range containment.
Market Psychology
An inside bar represents a temporal pause or "coiling" effect. Neither buyers nor sellers possessed sufficient conviction to push prices past the previous session's extremes, indicating equilibrium before an eventual volatility expansion.
To screen for inside bars across historical databases, definitions must be strictly mechanical.
Strict Inequality Formula
To qualify as an inside bar, both mathematical conditions must hold true simultaneously:
Hight < Hight−1 AND Lowt > Lowt−1
Qualification Tie-Breaker Rule
The inequalities are STRICT. If a bar's High equals the prior High, or its Low equals the prior Low (e.g., High(t) == High(t−1)), the bar does not qualify. It must be strictly narrower on both boundaries.
Single vs. Double Inside Bars
Single Inside Bar: A single period contained within its predecessor.
Double Inside Bar (I2): A rare multi-period contraction where two consecutive bars are contained. Bar 2 sits inside Bar 1, and Bar 3 sits inside Bar 2. Every double inside bar is a subset of the single inside bar population.
Bar 2 sits inside Bar 1, and Bar 3 sits inside Bar 2. Every double inside bar is also counted as a single.
Aggregation & Timeframe Mechanics
Timeframe
Sample Count (SPY Dataset)
Frequency Context
Daily Bars
509 Single / 21 Double
Routine volatility pause (~25 per year)
Weekly Bars
93 Single / 5 Double
Macro contraction (~4.7 per year)
Provisional Bar Note
If the current daily or weekly bar is trading inside its prior range, it is flagged as active in real-time logs but excluded from forward return calculations until the session or week officially closes.
Chapter 3
How Traders Use It
Trading Trend Continuation
Traders use inside bars to catch the continuation of an established trend.
Bullish Trend Continuation: In an uptrend, a Buy Stop order is placed slightly above the high of the parent bar (or the inside bar for a tighter entry). When price breaks above, it signals the trend is resuming.
Bearish Trend Continuation: In a downtrend, a Sell Stop order is placed slightly below the low of the parent bar (or inside bar). A break lower confirms trend continuation.
Risk Management & Trade Mechanics
Entry: Triggered automatically when price breaks the high or low boundary in the direction of the trend.
Stop Loss:
Tight Stop: Placed on the opposite side of the inside bar. This offers a high Risk-to-Reward ratio but is more vulnerable to small random moves.
Standard Stop: Placed on the opposite side of the parent bar, giving the trade more room to withstand minor fluctuations.
Profit Targets: Managed using fixed Risk-to-Reward multiples (e.g., 2R or 3R) based on the distance between the entry and stop loss.