Bid-Ask Spread
The bid-ask spread is the gap between the highest price a buyer offers and the lowest price a seller asks.
Also known as: spread
If the best bid is $99.90 and the best ask $100.10, the spread is $0.20. A market order buys at the ask and sells at the bid, so the spread is a cost you pay on every round trip.
Large, active coins have spreads of a hundredth of a percent; small coins can have spreads of several percent, which makes short-term trading in them expensive before fees are counted.