What Does Set Aside Mean?

Some trades cannot be read cleanly. We show those too, labelled, instead of quietly dropping them.

A trade is set aside when we cannot tell, from what the tape shows, whether it opened a position or closed one. Usually that means the prints were contested — size going both ways at the same strike within moments — or the open interest afterwards did not confirm either reading.

When that happens we do not pick the more interesting answer. The trade appears on the board, marked set aside, and it is not counted in the day's totals. Shown, not counted.

Why show it at all

Because the alternative is worse. A tool that silently drops what it cannot read looks more certain than it is, and you have no way to tell the difference between "nothing happened here" and "something happened and we could not interpret it". Those are very different things for anyone trying to decide how much weight to give a day's flow.

Set-aside trades are uncommon — on a typical session it is on the order of one flagged trade in fifty. If it were a quarter of the board, the board would not be worth much.

What it is not

Set aside does not mean the trade was small, suspicious, or unimportant. Some of the largest prints of a session end up set aside precisely because size arrived on both sides and the book was too thin to resolve it. It means one thing only: we could not read it cleanly, so we are not going to tell you we did.