Bid-Ask Spread
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In Brief
The bid-ask spread is the gap between the highest price buyers will pay for an asset and the lowest price sellers will accept — a built-in cost of every trade and one of the clearest signals of how liquid a market is.
What Is the Bid-Ask Spread?
The bid-ask spread is the gap between the highest price buyers are currently willing to pay for an asset (the bid) and the lowest price sellers are willing to accept (the ask). Every market has one, and it's a built-in cost of trading: buy at the ask, sell at the bid, and you're down by the spread before the price moves at all.
The spread is also the clearest quick read on a market's health: tight spreads mean deep, competitive markets; wide spreads mean thin liquidity and expensive trades.
How the Spread Works
Market makers and traders post bids and asks around the current price.
The difference between the best bid and best ask is the spread — the market maker's compensation for standing ready to trade.
When you trade instantly (a market order or a swap), you cross the spread and pay it implicitly.
In competitive markets, makers undercut each other and the spread narrows; in risky or quiet markets, it widens.
Why Spreads Widen
Low liquidity: few participants means less competition to quote tight prices.
High volatility: makers widen quotes to protect themselves from sudden moves.
Small or new tokens: uncertain value and thin trading make quoting risky.
Stress events: in panics, spreads blow out exactly when people most want to trade.
The Spread and Trust Wallet
When you swap in Trust Wallet, the quote you review before signing already reflects spread-like costs from the markets behind it — comparing the quoted output to the market price shows the real cost of the trade. The habit that matters is simple: always check what you'll actually receive, not just the headline price.