An inside bar is a period that stayed entirely within the previous one. It did not make a new high, and it did not make a new low.
About the Numbers in This Tutorial
The figures below were measured on SPY in July 2026, across the full price history the tool loads. Numbers like these move slowly, since each new session is one more observation in a very large sample, so expect small differences rather than different conclusions. The exception is the thin columns: where a reading rests on a handful of events, one more occurrence can swing it hard, which is the subject of Chapter 3.
The whole range, not the body
This pattern is about the full range, wick to wick. The high has to be lower than the prior high and the low has to be higher than the prior low. Where the bar opened and closed does not matter, and neither does its color.
That makes it the opposite emphasis to an engulfing candle, which ignores the wicks and looks only at the bodies. An inside bar is a statement about the extremes.
The test runs on the full wick-to-wick range. A single tick beyond either extreme and the bar does not count.
Why traders watch it
An inside bar is a pause. The market spent a whole period unable to push past what the previous one already established, which reads as a balance between buyers and sellers rather than a decision. Traders describe it as a coil, and the usual expectation is that a coil eventually releases.
Whether the release has a direction, and whether it is worth waiting for, is what the rest of this tutorial measures against a ticker's own history.
high < prior high AND low > prior low
Strictly less and strictly greater. A bar that matches the prior high or low exactly does not qualify.
That strictness is worth noticing, because it is the opposite convention to the engulfing pattern, where an exact tie does count. Here a bar has to be strictly narrower on both ends.
Single and double
The results come in two columns. A single inside bar is one bar sitting inside its predecessor. A double inside bar is one where the bar before it was also inside, so the range has narrowed twice running.
Every double is also counted as a single. The two columns are not separate populations, and the double column is always a small subset of the one beside it.
Daily and weekly
The Period toggle switches the whole analysis between daily bars and weekly ones. Weekly bars are built by grouping the daily history into calendar weeks, each week taking its highest high and lowest low, then the same two comparisons run on those.
An inside week is much rarer than an inside day, because a whole week has five chances to poke past the previous week's extremes. SPY has 509 inside days against 93 inside weeks.
Today's bar
If today is itself an inside bar, it appears in the count and in the log, but with no forward return yet. It sits out of the odds and averages until tomorrow's bar lands. The same applies to the current week until Friday's close settles it.
Worth Knowing
The rule ignores volume, trend, gaps, and how wide the bars were in absolute terms. A tiny pause inside a tiny prior bar counts exactly the same as a tight coil inside a huge one.
Chapter 3
Reading the Two Columns
Single on the left, double on the right, each with the same block of rows.
The context rows
Number of inside bars, the count over the ticker's whole record.
Times per year, that count spread across the years covered. This is the row that tells you whether you are looking at a routine occurrence or a rarity.
Last inside bar, the date of the most recent one, so you know whether the pattern is live or historical.
The continuation rows
Under the divider, forward performance measured from the inside bar's close at three distances: the next bar, the next 5, and the next 10. Each gives the green/red odds, then the average of the up outcomes and the average of the down outcomes separately.
As with the other tools in this family, "avg. green move" is the mean of the winners only and "avg. red move" is the mean of the losers only. Neither is a blended expectation, and reading one without the other will mislead you.
On SPY's single inside day the next-day odds are 54% green against 45% red, with the up days averaging +0.73% and the down days averaging −0.86%. Slightly more wins, slightly smaller wins. That combination is easy to miss if you only read the odds.
Reading Tip
Read "Times per year" before any percentage in the same column. It is the fastest way to know how much weight the numbers underneath it can carry, and it is the row people skip.
Chapter 4
When the Sample Runs Thin
This is the chapter that matters most on this tool, because the two columns sit side by side in identical formatting while resting on wildly different amounts of evidence.
The four boxes on SPY
Column
Occurrences
Per year
Next period green
Single inside day
509
25.5
54%
Double inside day
21
1.1
67%
Single inside week
93
4.7
53%
Double inside week
5
0.3
20%
Measured on 21 July 2026. All four percentages are rendered identically on the page.
What those percentages are made of
The single inside day's 54% comes from around 500 settled outcomes. It is a real measurement of a real tendency, even if a mild one.
The double inside week's 20% comes from five occurrences. One of them was green and four were red. Written as a percentage it looks like a powerful downside reading. Written as "one out of five" it is obviously nothing at all: flip a fair coin five times and getting one head happens often enough that nobody would blink.
The double inside day sits in between at 67%, which is 14 or so green out of 21. That is the kind of number that feels persuasive and is not. Twenty-one coin flips produce 14 heads or more roughly one time in five.
A percentage hides its own sample size. The page shows you the count directly above it for exactly this reason.
Why the rare columns look more exciting
Small samples produce extreme readings. That is not a flaw in the tool, it is arithmetic: with five events the only possible answers are 0%, 20%, 40%, 60%, 80% and 100%, so a thin column can never look moderate. The most eye-catching number on the page is often the least trustworthy, purely because it is the rarest.
The second control in the panel. It keeps only the inside bars that closed on one side of the ticker's 5-period moving average.
What it does
Above keeps inside bars that closed at or above the 5-bar average, which is roughly a pause during strength. Below keeps the ones that closed under it, a pause during weakness. Off keeps everything.
The moving average uses the same period as the analysis, so on the weekly view it is a 5-week average. The chart log shading honours the filter too, so what is highlighted always matches what is counted.
What it costs
Filter
Single inside days
Next day green
Double inside days
Next day green
Off
509
54%
21
67%
Above the 5MA
293
55%
11
73%
Below the 5MA
216
53%
10
60%
Measured on SPY, 21 July 2026. The filter roughly halves every sample it touches.
Look at the single inside day column: 54% becomes 55% above the average and 53% below it. Nearly 300 events on each side and almost no difference between them. That is a useful answer, and it is an answer you can trust because the samples stayed large.
Now look at the double column. Twenty-one events split into eleven and ten, producing 73% against 60%. That gap looks like the filter found something. It is eight green out of eleven versus six out of ten. Two different outcomes would reverse the ranking.
Common Mistake
Stacking filters on a rare pattern until a percentage looks good. Every filter you add makes the remaining sample smaller and the resulting number more extreme. Use the filter on the column with hundreds of events, and treat it with suspicion on the column with twenty.
The tool opens on a scanner. Two more views sit under the statistics once you open a ticker.
The landing table
Arriving without a ticker gives you a table of Ticker, Price, Inside Day Status and Inside Week Status, with My Watchlist and Top Signals tabs above it. Click a row to open that ticker's full analysis; the back arrow beside the title returns you.
Each status cell is a picture rather than a label. The prior period's high-to-low range is drawn as a grey band, and the current period's range so far is overlaid on the same price scale, green while it still fits inside and red once it has escaped. A check or a cross summarizes it, and hovering gives the actual prices.
The One Thing to Know Here
This status is live and provisional, unlike a pattern that has already formed. Every ticker starts the day showing a check, because a range that has barely begun is trivially inside the previous one. It flips to a cross the moment price exceeds yesterday's high or low. A check at 10am means very little; a check at the closing bell is the real thing.
The weekly cell behaves the same way across the week, resetting each Monday and only settling at Friday's close.
The event log
Under the statistics, a sortable log of every inside bar found, newest first, with its forward returns at each horizon. Click any header to sort. Today's bar, or the current week, appears with its forward columns unsettled, and those rows are excluded from the averages above.
The chart log
Below that, the price history as candlesticks with every counted inside bar shaded. Arrows step between occurrences and clicking a log row jumps the chart to that date. Because the shading respects the 5MA filter, this is also the quickest way to see what a filter actually removed.
Both views have their own guided walkthrough built into the tool. Open either one with the tour already running: