The chart display is fully customizable. You can switch the unit of account between SOL and USD. Additionally, you can toggle the main chart to display either the token's price or its total market cap.
As a common trading practice, many users prefer to view the token price in SOL and the market cap in USD.
If you ever notice a discrepancy between the value shown on the chart and the value in the token information panel on the right, simply click the toggle button to synchronize them.