Policies will allow you to alert on cost increases.
Below is an example of what a potential policy would look like:
A policy configured in this way will evaluate the last 2 full days of costs that are available in the platform. In this case, an alert will be sent when the platform identifies a 15% or higher increase between these two days that are being evaluated.
It's a best practice to configure an action, such as email, to send an email alert when these increases are identified.