Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of American Public Education (APEI 2.25%) were getting sent to the principal's office today, falling as much as 22% after a disappointing fourth-quarter earnings report.

So what: The for-profit educator delivered a per-share profit of $0.51, down from $0.74 a year ago and short of expectations of $0.54, while revenue edged down 4% to $82.9 million, better than the analyst consensus at $81 million. Those figures may have evened each other out, but the company saw new student course registrations decline by 10% at its principal American Public University school, which the company believed was due in part to tuition assistance cuts from the Department of Defense.   

Now what: American Public Education's outlook was also weak, as it expects a first-quarter revenue increase of 0%-3%, and EPS of $0.43-$0.48, well below estimates of $0.67. New student course registrations are also projected to decline by 7%-9%. This industry has seen a contraction over the past couple of years due to increasing regulatory pressure and student skepticism, but several other educator stocks are on the rebound as their enrollment figures seem to be bottoming out. Today's report makes clear that American Public Education has not yet turned the corner, and with profits falling 30%-40%, this stock may have further to fall.