Where does the initial balance start on a 24-hour market?

At the regular session open rather than the electronic one, because the concept assumes a cash open that concentrates participation. Instruments with no cash session, crypto for instance, have no natural anchor: pick one, record it, and never compare profiles built on different anchors.

Is a narrow initial balance a signal to buy the break?

No. It says the day has range left, not which way the range lies. Both edges are candidates for the same reason, and preferring the one that suits a position you already hold is a preference, not a reading.

One hour or thirty minutes?

Either, provided you fix it. A shorter initial balance is exceeded more often for purely mechanical reasons — less range to clear — so the two conventions produce different base rates and cannot be compared. Log which one you use beside every observation.

Glossary

Initial Balance

Also called: IB · first-hour range · opening range

The initial balance is the high and low of the first hour of the regular session. It frames the day: a narrow initial balance is more often extended, a wide one tends to contain the session. Its two edges accumulate resting stop orders, which is why price reacts there.

What the first hour measures

The initial balance is a market profile term: the range covered by the first two 30-minute TPO periods of the regular session. One hour, high to low, nothing else. It measures how much price the market had to cover before the earliest participants settled on a range.

The hour is a convention, not a law: two lettered periods was simply the natural unit on a paper profile. Thirty or ninety minutes is equally defensible, provided you never change it halfway through a study.

Narrow and wide are relative words

A narrow initial balance means the opening auction settled quickly: little was contested, and the day still has range left to distribute. A wide one was fought over immediately, and the session more often stays inside it. That is the whole idea, and it is a statement about range, not direction.

The trouble is that narrow has no absolute value: ten points is narrow in one volatility regime and wide in another. Normalise before you use it — divide by the median initial balance of the last twenty sessions, or by the current average true range. A ratio survives a change of regime; a point value does not.

Why the edges react

The two extremes are the most published numbers of the morning. Breakout orders sit above the high and below the low, protective stops from first-hour positions sit behind them, and both fire the same way when an edge gives way. An extension is partly its own fuel: the move draws in the orders that extend it — trapped traders and a liquidity sweep seen from two angles.

You will see it quoted that some large majority of sessions extend one side of the initial balance, and that narrow ones extend more often. The direction of the claim is mechanical and plausible; the number is not. No public dataset backs it, narrow and extension mean different things to everyone quoting it, and the sessions where it failed are in nobody's slide deck. Measure it on your own instrument, under your own definition, or do not quote it.

A worked example

In a synthetic ES session, the first hour prints a high of 5 341.25 and a low of 5 333.50: 7.75 points, 31 ticks. The median initial balance across the previous twenty sessions of the same synthetic series is 13.50 points, so this one is 0.57 of normal — narrow under a definition written before the open, not after it.

Price clears 5 341.25 in the third period. One initial balance width added to the break puts the mechanical extension objective at 5 349.00; the session reaches 5 350.75 and closes beneath it. Note what the objective did and did not do: it gave a place to measure the move against, not a reason to be in it.

The trap

Treating the first hour as informative regardless of what filled it. A scheduled release fifteen minutes after the open does not produce an opening auction; it produces a reaction, and the range it leaves is a news range wearing the initial balance's name. Check the calendar before you read the shape.

The other half is the fixed threshold. If your rule says narrow is under eight points, it silently changes meaning every time volatility shifts — and you will not notice, because the rule itself never changed.

Frequently asked

Where does the initial balance start on a 24-hour market?: At the regular session open rather than the electronic one, because the concept assumes a cash open that concentrates participation. Instruments with no cash session, crypto for instance, have no natural anchor: pick one, record it, and never compare profiles built on different anchors.
Is a narrow initial balance a signal to buy the break?: No. It says the day has range left, not which way the range lies. Both edges are candidates for the same reason, and preferring the one that suits a position you already hold is a preference, not a reading.
One hour or thirty minutes?: Either, provided you fix it. A shorter initial balance is exceeded more often for purely mechanical reasons — less range to clear — so the two conventions produce different base rates and cannot be compared. Log which one you use beside every observation.