Scalping means dozens of short trades on small moves. An order book scalper trades not off indicators but off large orders visible in the book.

What a wall is

A wall is a large limit order, or a cluster of orders at one price, noticeably bigger than its neighbours. It can stop price: to move further, the market has to eat through the whole size.

The core idea

The scalper waits for price to reach the wall and enters off it with a stop right behind it. If the wall holds, they take a small move away from the level. If it gets eaten, they exit with a small loss, and sometimes flip in the breakout direction, because a move often speeds up after a wall is taken out.

How to tell a real wall

The main sign is how long it lives. An order that sits for hours and does not move as price approaches is real. One that appears and disappears or runs away from price is most likely spoofing. On the order book heatmap the difference is obvious: a real wall is a long bright band, a spoof is a short flicker.

Risks

Scalping takes discipline and low fees: with dozens of trades a day, fees eat a large share of profits. Leverage magnifies both gains and losses, so the stop goes in before the entry, not after. Large orders for the main coins are collected on the whale orders page.