It might be due to calculating the spread or price difference between supply and demand.

“Spread” refers to the difference between the buy and sell price.

The difference between the price offered by the buyer and the price provided by the seller is called the bid-ask spread.

When there’s a wider spread, that means there’s a bigger difference between the two prices, so there’s usually less liquidity and more volatility here. On the other hand, a lower spread indicates low volatility and high liquidity. Therefore, the price will bear a smaller spread when trading a currency pair with a tighter spread.