This type of notifications are available for all CoinStats users and are turned on by default.
They are being fired if a coin in users portfolio or favorites is going up or down more than a specific % in last 1 hour.
For example, notification will fire to all Neo holders if it goes up 5% or more during the last 1 hour. We're always adjusting percentages based on coin rank and volume to make notifications as useful as possible.
You can turn off and on your significant change notifications from alerts tab on the bottom of the screen. This will enable notifications for all the coins you have in your portfolio or favorites.
You can also turn off and on significant change notifications for any specific coin you'd like, as presented in the images below: