Reading an Order Book

What is an Order Book?

Every crypto exchange has an order book — a real time list of all open buy and sell orders for a trading pair.

Think of it like a marketplace notice board where buyers post “I want to buy at this price” and sellers post “I want to sell at this price.”

Understanding the order book gives you a huge advantage over traders who just look at price alone.

Structure of an Order Book

An order book has two sides:

Buy side — Bids
All open buy orders listed from highest price to lowest.
Shown in green.
These are buyers waiting for sellers to meet their price.

Sell side — Asks
All open sell orders listed from lowest price to highest.
Shown in red.
These are sellers waiting for buyers to meet their price.

The middle — Last traded price
The most recent price at which a trade actually happened.

Key Terms

Bid
The highest price a buyer is currently willing to pay.

Ask
The lowest price a seller is currently willing to accept.

Spread
The difference between the best bid and best ask.

Tight spread = liquid market = easy to trade
Wide spread = illiquid market = risky to trade

Example:

• Best bid: $79,950
• Best ask: $80,000
• Spread: $50

If you place a market buy — you pay $80,000.
If you place a market sell — you receive $79,950.
The $50 spread is essentially a cost of trading.

Market Depth

Market depth shows how much volume exists at each price level.

Large buy walls
A huge amount of buy orders clustered at one price level. This acts as strong support — price tends to bounce from here.

Large sell walls
A huge amount of sell orders at one price level. This acts as strong resistance — price tends to struggle to break through.

Professional traders watch order book walls carefully. When a large wall disappears suddenly — it often signals a big price move is coming.

Order Book and Price Movement

When buyers are aggressive:

• More market buy orders hitting the ask
• Ask side depletes quickly
• Price moves up

When sellers are aggressive:

• More market sell orders hitting the bid
• Bid side depletes quickly
• Price moves down

Spoofing — The Dark Side

Not all order book entries are genuine. Some traders place large fake orders to manipulate price perception — then cancel them before they fill.

This is called spoofing and is illegal on regulated exchanges but common on unregulated ones.

Never make decisions based solely on large order book walls — they can disappear in seconds.

Practical Tips

• Always check spread before placing a market order
• Wide spread = use limit orders only
• Watch for sudden disappearance of large walls
• High volume on bid side = bullish pressure
• High volume on ask side = bearish pressure

In the next topic we will learn about trading pairs and how cryptocurrency prices are quoted.