The cause of the score drop and the reason for the alert were unrelated. The alert was for the lowered balance and it also shared your EX score at that time. However, the cause of the drop could have been anything that occurred between the alert date and the date of your previous EX score. If you would like to post the source of your alert and scores and the full details of your profile before and after the change we can help you look for the likely cause of the drop.
MyFICO alerts don't provide reasons for a score change. There are certain events which trigger MyFICO alerts. If there happens to be any difference between your present score at that particular bureau and the previous score reported to you from that bureau, the score change is tacked on to the alert. There is not necessarily any connection at all between the score change and the alert substance.
MyFICO explains this in the "learn more" link contained in the alert:
"Why did my score go up when I got an alert for something negative (or why did my score go down when I got an alert for something positive)?
The short answer: Your FICO(TM) Score may change because of other events not monitored by an alert.
Whenever we send you a credit alert, we also send an updated FICO Score. To ensure you get the most current score, we calculate it based on your entire credit report at that point in time - not just the new information on the alert. This means your new score may reflect other changes that are outside of the things we watch for (see everything we monitor).
Sometimes you may see your score increase when you think it should've decreased, and vice-versa, but you'll always have your most up-to-date and accurate score."
