Level 2 - the order book, or market depth - displays the resting limit orders beyond just the best bid and ask. You see the layers of buyers below and sellers above, and how much size sits at each price. Level 1 is the top of the book; Level 2 is the whole stack.

What it reveals

The book shows where liquidity lives. A thick cluster of buy orders below can act as short-term support; a wall of sell orders above can cap a move. Thin books mean price can travel far on modest volume - the setup for fast moves and slippage.

Why it deceives

The book is not truth - it is intention, and intention can be faked. Large orders posted to create the impression of support or resistance can be pulled the instant price approaches ("spoofing," which is illegal but happens in gray forms). A visible wall can vanish; hidden orders never appear at all. The book shows what people want you to see as much as what they will actually do.

The order book is a poker table. Some of the chips on display are a bluff.

Book plus tape

Depth is most useful paired with the actual prints - the time and sales that show what filled. A wall that keeps absorbing real sell orders without breaking is meaningful; a wall that no one tests is just a display. Read intention and execution together, not the book alone.