Open types and day types
The first thirty minutes tell you who is in charge. Classify the open, then the day, and stop trading every session the same way.
01The first hour is a conviction meter
Stand outside a department store on the morning of a genuine liquidation sale and watch the crowd when the doors unlock. Nobody browses. People walk fast, all in one direction, straight to the thing they came for, and the aisles behind them stay empty. Now watch the same doors on an ordinary Tuesday: shoppers drift in, pick something up, put it back, wander toward the entrance again. You do not need a single receipt to know which morning had conviction. The first few minutes of foot traffic already told you.
The 08:30 futures open is that unlocking of the doors. Overnight, ES trades in a thin crowd: Asia, London, a few desks. At the open, the deepest pool of participants of the entire day arrives at once, and everyone who positioned overnight must now face them. Suppose the overnight session bought its way from 5,636 up to 5,654. If the day session opens at 5,650 and immediately trades down through 5,644, every one of those overnight longs is underwater within minutes, and their exits become fuel for the move against them. The open is not just a price; it is the moment the market audits whoever traded in the dark.
So the first thirty to sixty minutes answer two questions no indicator can: is anyone urgent today, and on which side? A market where a big-timeframe participant must buy behaves like the liquidation-sale crowd, leaving the open fast and not returning. A market where nobody is urgent behaves like the Tuesday shoppers, milling around the opening print. Everything in this chapter is a vocabulary for those two kinds of foot traffic.
02Four ways to leave the open
Your yardstick is a single price: the opening print. Watch what the auction does with it. The strongest signature is the Open-Drive: price leaves in one direction within the first minutes and never trades back through the open. Someone arrived with size and a decision already made overnight; they are not negotiating. It is also the earliest recognizable type, sometimes within five or ten minutes. Next is the Open-Test-Drive: price probes one side of the open, finds no business there, then turns and drives the other way. The failed probe is a gift, because that test very often stands as the day's extreme, which means the market just handed you the best-defined risk point of the session.
The Open-Rejection-Reverse starts like a drive: price leaves the open with apparent conviction, travels, then gets rejected mid-morning and reverses back THROUGH the open. The initiating side had real intent but the responsive side proved stronger, so conviction is moderate and shared, and you cannot label it until the reversal actually recrosses the open, often thirty to sixty minutes in. Last is the Open-Auction: price rotates around the opening print with no conviction at all, a few points up, a few points down, back again. Here you must split by location. An Open-Auction INSIDE yesterday's range is honest sleepiness: nobody urgent showed up, expect rotation. An Open-Auction OUTSIDE yesterday's range is the dangerous quiet one: price is far from the last agreed value, yet nobody is correcting it. The market is auctioning calmly in a place with no history of two-sided trade, and when that stand-off resolves it tends to resolve violently, because there is nothing agreed nearby to catch it.
03Day types: how many timeframes showed up
The open is the seed; the Initial Balance frames it. The IB is the range of the first hour, periods A and B, and the day type is simply the story of what the market does with that frame: how far it extends beyond it, on how many sides, and where it closes. A Trend day extends in one direction essentially all session. The IB is a small fraction of the final range, often under a third, every period does business beyond the last, and the close sits near the extreme. One timeframe is in control and the other never seriously answers. This is the day you must NOT fade, at any hour, on any 'overbought' feeling.
A Normal day is the opposite temperament: a wide IB, then little or no range extension, with responsive traders selling the top of the frame and buying the bottom. A Normal Variation day, the most common of all, extends the IB in one direction to roughly double its width and then finds balance up there. The interesting pair is the last one. A Neutral day extends BOTH sides of the IB: initiative buyers break the top, initiative sellers break the bottom, two timeframes are openly fighting. If the fight ends where it started, close in the middle, that is Neutral. If one side wins the last hour and the close prints at an extreme, that is Neutral-Extreme, and the late winner is real information for tomorrow's open.
The silhouettes are easier to compare than to describe, so the stage carries five of them side by side on one price grid and one clock: four of the types just named, plus a Double Distribution day these paragraphs do not describe. Neutral-Extreme is not a sixth silhouette; it is the neutral shape with the close parked at one end instead of the middle, which is why it is taught inside the neutral day rather than given a stage of its own. Pick a type and watch it assemble period by period: the question under every one of them is what the session did with the frame the first hour drew.
A Trend day up, drawn as a profile. Read the shape before the caption: the IB is the thin base, and every letter after B lives higher than the letters before it.
Now the same drawing exercise for a Neutral day. Notice how different the silhouette is: a fat belly, and lonely letters sticking out of BOTH ends of the IB.
04The working rule set: IB width, ATR and a revision schedule
You now have two measurable inputs by 09:30: the open type you logged in the first half hour, and the IB width divided by a recent average range, say the 10-day average RTH range as your ATR yardstick. Neither input alone classifies a day; together they concentrate the odds hard. A narrow IB is an unfinished frame, easy to extend; a wide IB is a finished one, hard to leave. Cross that with the conviction ladder from section 02 and you get a small probability table worth more than most indicators.
The figure runs one of those revisions on a morning of its own. Periods A and B fix a sixteen-point frame, C trades eight points clean through the top of it, and both endings print identically that far; only the next two periods differ. Flip between them: one ending pays for the higher prices and drags value up behind the break, the other hands every tick back inside the frame within thirty minutes. The break was never the information. What answered it was.
05Check yourself
06What the engine does with this, and the next question
This taxonomy is not decoration; it is the exact conditioning variable behind the engine's opening odds. At 09:00 the engine labels the open with the same four types you just learned, measures the developing IB against recent ATR, and publishes P(IBH) and P(IBL): the probability that the initial balance high or low breaks. A drive up out of value with a narrow frame pushes P(IBH) toward the high 70s and starves P(IBL); an in-range auction open leaves both near coin-flip territory. Every one of those calls is graded against what the session actually did, which is why the numbers deserve more trust than a hunch.
One question is still open, and it is the subject of the next chapter. Two mornings can print the identical Open-Drive up with the identical narrow IB, yet mean different things, because one drove higher out of yesterday's value and the other drove back INTO it. Where value is forming today relative to yesterday, higher, lower, inside or overlapping, is the coordinate system every open type lives in. Chapter 4 builds it.