Overnight inventory

Somebody spent the night buying. When the American session opens, the rest of the market gets to say whether it agrees — and positions taken in a thin book have to be closed in a deep one. That exchange is the first real event of the day.

Mak · 3 min read · Stage 5, article 3 of 8

What the phrase means

Overnight inventory is the positioning that accumulated between yesterday's close and today's open. Nobody publishes a figure for it, so it is read from where the trading happened relative to yesterday's settlement price:

Net long — most of the overnight activity took place above the settlement. More buying than selling, in aggregate.
Net short — most of it happened below.
Balanced — it traded around the settlement, and there is not much to say.

It is an inference from where price spent the night, not a measurement of anyone's book. Like most useful things in this path, it is a reasonable reading rather than a fact.

Why one-sided positioning matters

Because of something already established in the first stage: overnight, the book is thin. Fewer participants, less resting size, and moves that need less to produce them.

So a strongly one-sided night is a position that was built cheaply, in a market where it was easy to push, by a smaller crowd than the one about to arrive. When the session opens, that crowd shows up all at once and either agrees or does not.

And there is a mechanical consequence people skip: whoever is long overnight has to sell to close, whatever they think. A position is an obligation to trade in the opposite direction later. A heavily one-sided night is therefore a stack of future orders pointing the other way, waiting for a reason.

Diagram 1. The overnight session sets up the question. The first part of the American session answers it, and the answer is worth more than the question was.

The two answers

The night gets unwound: The arriving participants do not support the overnight direction. The positions built in the quiet hours are closed — which means trading against them — and price works back towards where the previous session found agreement.
The night gets confirmed: Volume arrives on the same side. The overnight move was not thin-book drift but an early version of what the whole market thinks, and the day continues away from yesterday's range into prices nobody has traded recently.

The second case has a consequence worth naming: once price is trading well away from the previous session's range, yesterday's levels stop describing anything. The market is finding out what a new area is worth, and references built in the old one are arguing about a different place.

How to use it, honestly

This is a question to hold at the open, not a signal to act on. Written out, it is short:

Where did the night trade, relative to yesterday's settlement?
Was it one-sided, or did it go both ways?
In the first part of the session, is the arriving volume supporting that positioning or working against it?

Everything else in this stage helps answer the third. And notice that all three questions are about what has already happened — which is the only kind of question this path will ever teach you to ask well.

The next article is about the visible mark all of this leaves on a chart: the gap.