Every time you buy or sell crypto on an exchange — you pay the spread. Most traders do this without realizing it because exchanges don't show it as a separate line item. But it's real money leaving your account on every trade.
What Are Bid and Ask
Open any exchange and look at ETH/USDT. You'll see two prices:
Bid — the highest price someone is currently willing to pay to buy ETH right now.
Ask — the lowest price someone is currently willing to accept to sell ETH right now.
Example:
Ask: $2,484.50 ← sellers will sell at this price
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Bid: $2,484.00 ← buyers will buy at this price
Spread = Ask − Bid = $2,484.50 − $2,484.00 = $0.50
As a percentage: $0.50 / $2,484.00 × 100 = 0.020%
Why Spreads Exist
Spreads exist because buyers and sellers always disagree slightly on fair value:
- Buyers want to buy cheaper
- Sellers want to sell higher
- The spread is the gap between their expectations
The more liquid a market (more participants, higher volume), the narrower the spread — competition between buyers and sellers compresses the gap.
How Spreads Affect Your Trades
With a market order:
- Buy → fills at the Ask price (higher)
- Sell → fills at the Bid price (lower)
Example: You buy 1 ETH at $2,484.50 (Ask) and immediately sell. You sell at $2,484.00 (Bid). Loss from spread alone: $0.50 (0.02%).
This is before exchange trading fees (0.10%). Total market order cost: 0.02% (spread) + 0.10% (fee) = 0.12% per side.
Types of Crypto Spreads
Bid-Ask Spread (intra-exchange)
As described — the gap between best buy and sell price on one exchange.
Typical values:
| Pair | Exchange | Bid-Ask spread |
|---|---|---|
| BTC/USDT | Binance | 0.01–0.02% |
| ETH/USDT | Binance | 0.02–0.04% |
| SOL/USDT | Bybit | 0.03–0.06% |
| ALT/USDT (low-cap) | KuCoin | 0.5–3% |
Cross-Exchange Spread
Price difference for the same asset between different exchanges. This is the foundation of crypto arbitrage.
SpreadScan tracks cross-exchange spreads across 600+ pairs in real time — open scanner →
Total Cost of a Trade
| Cost type | Who receives it | Amount |
|---|---|---|
| Bid-Ask spread | Market makers | 0.01–3% |
| Exchange fee | Exchange | 0.08–0.26% |
| Slippage | Market | 0–1%+ |
For BTC/USDT on Binance, total round-trip cost: ~0.22% minimum.
This is why profitable arbitrage requires a cross-exchange spread above 0.4–0.5% — to cover all these costs.
Conclusion
The spread is an invisible but real cost of every trade. Understanding it helps you accurately calculate trading costs, choose liquid pairs, and properly evaluate arbitrage opportunities.
View cross-exchange spreads in SpreadScan →
FAQ
Is the bid-ask spread the same as exchange commission? No. Exchange commission is a fixed percentage the exchange charges. The bid-ask spread is the price gap between buy and sell prices — it goes to market makers, not the exchange.
Why do some coins have huge spreads? Low liquidity. If a coin trades with small volume, few participants post orders — the bid-ask gap is wide.
How do I reduce spread costs? Trade liquid high-volume pairs, use limit orders instead of market orders, trade during peak activity hours.