When configuring a custom alert you may come across the terms Spike and Plummet in Step 2.
A spike or plummet is defined as an increase or decrease of two standard deviations from the mean of the previous fifteen days.
Spike in Share of Voice
This alert triggers when the share of voice for an app significantly increases compared to its share of voice over the last fifteen days. For example, if an app jumps from 2% share of voice to 6% share of voice suddenly, this alert will trigger.
This will tell you when a competitor is increasing their ad spend and allow you to analyze why they are doing a burst campaign.