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Beginner 6 min read

Who's Buying, Who's Selling

The live order book — a real-time record of every buyer and seller

Note: The order book is the live engine behind every price you see. Once you understand it, you stop wondering "why did the price move?" and start seeing the actual mechanics driving it.

What Is an Order Book?

An order book is a real-time, constantly-updating list of every open buy and sell order for a trading pair. Think of it as the marketplace's public ledger — every trader who has placed an order but hasn't had it filled yet shows up here.

It shows exactly how much demand exists at each price level and how much supply sellers are offering. It's the most direct window into what the market actually thinks — not what people say, but what they're putting money behind.

On CoinSparring, the order book you see on the Exchange page streams live data from the real market. That means you're looking at real demand and supply, updating in real time.

Tip: Spend a few minutes just watching the order book on a liquid pair like BTC/USDT. Notice how orders appear and disappear rapidly — that's the market "breathing," a constant negotiation between buyers and sellers.

Buyers vs Sellers

Every order in the book is either a buy order (also called a "bid") or a sell order (also called an "ask"). They're always listed separately, buyers below the current price and sellers above it.

Sellers at (USDT)Amount (BTC)
67,350.002.100
67,380.000.215
67,395.001.540
67,420.000.872
67,450.000.324
$67,330.00Last price · Spread: $40.00
67,310.001.820
67,290.000.560
67,265.000.934
67,240.000.123
67,200.003.450

Buyers (green)

Listed below the current price, highest to lowest. The top bid is the best price any buyer is currently willing to pay — your sell orders fill at or near this price.

Sellers (red)

Listed above the current price, lowest to highest. The lowest ask is the cheapest price any seller is currently accepting — your buy orders fill at or near this price.

The Spread

The spread is the gap between the best buy price and the best sell price. It's the cost of entering and exiting a position immediately — you buy at the ask and sell at the bid, and the spread is the difference you pay.

In the mock order book above, the spread is $40 ($67,350 ask minus $67,310 bid). That means if you bought at the best ask and immediately sold at the best bid, you'd lose $40 per BTC before any fees. On major pairs like BTC/USDT, the real spread is usually less than $1.

Tight spread (BTC, ETH)

Less than 0.01% — a sign of high liquidity. Many buyers and sellers are competing, keeping prices close together. Low cost to enter and exit.

Wide spread (small altcoins)

Can be 0.5%–5%+ on illiquid pairs. Far fewer participants, so buyers and sellers sit far apart. High hidden cost per trade, even before fees.

Tip: Always check the spread before trading a new coin. A wide spread means you start every trade at a loss — price has to move in your favor just to break even. Stick to high-volume pairs with tight spreads.

Reading Market Depth

Market depth is the total volume of orders at each price level, and how deep you have to go into the book to fill a large order. A steep curve means thin liquidity; a shallow slope means abundant liquidity.

In the order book visual above, the background bars behind each row show relative size — wider bars mean more volume at that price. Some levels have much larger orders than others. These act like walls — support or resistance that price needs real pressure to push through.

What to look for in market depth:

Buy wallA very large buy order significantly below the current price. Acts as a strong floor — sellers know buyers are waiting there. Can be a bullish signal.
Sell wallA very large sell order above the current price. Significant resistance — price often struggles to push through without high buying volume.
Thin bookFew orders on either side. Price can move rapidly on relatively small trades. Common in low-volume altcoins and during off-hours. Higher volatility risk.
Heads up: Large orders in the book can be cancelled instantly. "Walls" aren't guaranteed support or resistance — some traders place large fake orders to shape perception, then cancel them before price arrives. This is called "spoofing."

How Orders Fill

Understanding how orders fill helps you trade at the price you actually want. There are two ways to execute:

Market orderFast

Fills immediately at the best available price. Your buy matches the lowest available ask; your sell matches the highest available bid. Fast, but you don't control the exact price — in thin markets you may fill worse than expected (called slippage).

Limit orderPatient

You set the exact price you want and wait for the market to come to you. Place a limit buy at $67,000 while BTC trades at $67,330, and your order sits in the book until price drops to $67,000 — or you cancel it. No slippage, but no guarantee of a fill.

When your limit buy sits in the book and price drops to your level, a seller's order matches against yours — your order "fills" and you receive the asset. Large limit orders may fill partially across several price levels if there isn't enough volume at exactly your price.

Tip: For most trades on CoinSparring, market orders are perfectly fine — BTC and ETH have such deep liquidity that slippage is negligible. For smaller altcoins, consider a limit order to avoid paying a wide spread.
Key takeawayThe order book is just buyers and sellers lining up their prices — the spread is what it costs to trade right now, and market orders trade speed for certainty while limit orders trade patience for control.

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Practice on CoinSparring

Open the live order book and watch real market depth in action.

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