# Rate of Change & Rate of Change Percent

**Rate of Change** is simply the net change in Price over the selected period. In the Daily chart below, IBM is down -$20.64 compared to 50 days ago. The **Rate of Change Percent** reflects the same reading on a percentage basis. IBM is down -11.83% over the last 50 days.

ROC |
`C - Cx` |
`x` =Period |

ROC% |
`100 * (C / Cx - 1)` |

Where `x`

is the period which must be an integer.

### Examples

A 50 period rate of change can be written as follows.

`C - C50`

A 50 period rate of change percent can be written as follows.

`100 * (C / C50 - 1)`