The most common reasons for why Trading Alerts turn off are:
Your alert was triggered and the notification was sent. Confirm the trigger value and how you chose to be notified.
A corporate action on one of the underlying motif securities took place. Once the corporate action is processed you will be able to re-enable your alert. Corporate actions take about 2-3 days to process.
There was a trade on one of your positions that is tracked by a Trading Alert. You can re-enable your Trading Alert at any point from the Trading Alerts page or positions page.
For more information on why your alert was disabled please contact Customer Service at 1-855-586-6843