Line chart is one of the simplest methods of graphical presentation of changes in value of financial instruments.
The line chart consists of the last price at which the security was traded (closing price) on a given trading day. Final price should have, according to some analysts greater predictive value. The biggest advantage of a regular graph is good transparency, while the main disadvantage of this type of display is smaller set of information on price movements of a financial instrument.
For example, if you are using the closing price of each event to draw a line chart, then it is not possible to determine the range (during the day, which rates were traded) or the exchange rate at the opening of each event.