Walls in the order book

A large resting order close to price is either a level that holds or a level whose break starts a move. The walls board collects them from every book the server is listening to live and sorts them by size.

What the board shows

Market, side, size, distance from the mid and age — largest first. Size is the notional resting on the level; distance says how far the level sits from the middle of the book: minus below, plus above.

Two filters decide what you see at all: a minimum size and a maximum distance. A wall three percent from price and one three tenths of a percent away carry different weight, and the second filter exists precisely so they do not land in one list.

Age is half the meaning

An order that has stood for minutes and one that appeared a second ago read differently. A wall that appeared and vanished without ever being traded is a spoof — its own kind of signal, because a pulled order is usually a pulled intention.

The opposite case is absorption: price is hit and does not move, because somebody is taking the whole flow quietly. Here the signal comes not from the resting order but from the mismatch between aggression and result.

Where the data comes from

Walls are visible only through live books, and not every exchange streams one — the board names the ones it is reading on itself. With no live books it says it is blind rather than saying there are no walls: an empty list and missing data are two different answers and must not be confused.