Bid-Ask Spread
By Menno — 13 years in crypto, 3 bear markets survived, zero paid promotions
Last updated: March 2026
The bid-ask spread is the difference between the highest price a buyer will pay (bid) and the lowest price a seller will accept (ask), representing the implicit transaction cost of an immediate trade.
The bid-ask spread is the built-in cost of trading. If Bitcoin's bid is $50,000 and the ask is $50,050, the spread is $50 — or 0.1%. When you buy at market, you pay the ask price; when you sell at market, you receive the bid price. This means even without any exchange fees, every round-trip trade (buy + sell) costs you the spread twice.
Spread width is primarily determined by liquidity. Highly liquid markets (Bitcoin on major exchanges) have extremely tight spreads — often $1-5 on Bitcoin, representing 0.002-0.01% at current prices. Small-cap altcoins on low-volume exchanges can have spreads of 1-5% or more, making them extremely expensive to trade actively. This is why market makers (who provide liquidity by posting both bids and asks) are compensated with the spread — they take on inventory risk in exchange for the spread profit.
For retail traders, the spread is often more significant than the exchange fee. A 0.3% exchange fee sounds small, but combined with a 0.5% spread on a volatile altcoin, you're paying 0.8% on entry alone — 1.6% for a round-trip. Multiplied over frequent trading, this compounds into substantial drag on returns. The practical implication: use limit orders rather than market orders to avoid paying the spread. With a limit order set at the current bid price, you capture the spread rather than paying it. High-frequency trading exists primarily to profit from the bid-ask spread through market-making strategies.
Frequently Asked Questions
How does the bid-ask spread affect my crypto trading costs?
Every time you buy at the ask and sell at the bid, you pay the spread. On liquid pairs like BTC/USDT on Binance, this is negligible (0.01-0.05%). On low-liquidity altcoins, spreads can be 1-5%, making active trading prohibitively expensive. Always check the spread before placing market orders on low-cap tokens.
How can I avoid paying the full bid-ask spread?
Use limit orders instead of market orders. Set your buy limit order at or slightly above the current bid price; set your sell limit at or slightly below the ask. This way you're posting liquidity and may get filled at a better price. You won't always get filled immediately, but you avoid the cost of taking liquidity at market prices.
Related Terms
Order Book
An order book is a real-time list of all pending buy and sell orders for a trading pair on an exchange, showing the price and quantity of each order awaiting execution.
Slippage
Slippage is the difference between the expected price of a trade and the actual execution price. It typically occurs in low-liquidity markets or with large orders, and can significantly increase the cost of trading.
Liquidity
Liquidity is how easily an asset can be bought or sold without significantly moving its price. High-liquidity assets like Bitcoin have tight bid-ask spreads, while low-liquidity altcoins can experience large price swings from small trades.
Market Order
A market order is an instruction to buy or sell an asset immediately at the best available current price, guaranteeing execution but not the exact price.
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