Bid-ask spread

The bid-ask spread is the gap between the highest price a buyer is currently willing to pay (the bid) and the lowest price a seller is willing to accept (the ask). If the best bid for bitcoin is ₹74,90,000 and the best ask is ₹75,00,000, the spread is ₹10,000, or about 0.13%.

The spread is a hidden trading cost. If you buy at the ask with a market order and immediately sell at the bid, you lose the spread even if the price has not moved. Liquid markets, such as BTC/USDT on large exchanges, often have spreads of a fraction of a basis point; small tokens or thinly traded INR pairs can have spreads of several percent.

"Instant buy" features in some apps hide the spread by quoting a single price, which can be noticeably worse than the order-book price. Using limit orders, choosing liquid pairs and checking the order book before trading can reduce what you pay.