# Cumulative return

In this article, you'll learn about cumulative return and how it's calculated in Composer.

** What is cumulative return?**

The cumulative return is the percent change in the value of an investment over a given time period.

**An example**

Let’s take a look at an example. In this backtest, we see the symphony’s cumulative return is 38.2%. That means that this symphony’s value increased by 38.2% over the length of the backtest period.

**What is the formula?**

**What is the step-by-step calculation?**

Let's go through the calculation of the cumulative return step-by-step for a symphony backtest. Here's how we do it:

- Start with the value of the symphony on the final (i.e., the most recent) trading day of the backtest.
- Subtract the value of the symphony on the first trading day of the backtest.
- Divide by the value of the symphony on the first trading day of the backtest.
- Multiply the resulting value by 100.