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: Someone apparently forgot to bring the apple to Wall Street this morning, with shares of secondary education company Strayer Education (Nasdaq: STRA) getting drubbed by 14% in intraday trading following its second-quarter earnings report.

So what: The traditional classroom and Internet education company's second-quarter results weren't all that bad. The company beat EPS estimates by $0.14 and just marginally missed revenue projections, coming in at $163.8 million versus the $166 million consensus. Where shareholders really got a rude awakening was in Strayer's third-quarter guidance. New student enrollment plunged 21%, while continuing student enrollment fell 5%, which contributed to the company's EPS guidance of $1.04-$1.06. This is a mile short of the $1.37 the Street had been looking for.

Now what: New government regulations concerning who qualifies for financial aid appear to be hitting home for the online education sector. This week, ITT Educational Services (NYSE: ESI) also reported a mammoth 19.9% drop in new student enrollment. With much of the sector still to report, this has all the makings of a bloodbath. Perhaps the only company with any momentum heading into earnings season in this sector is Rising Star buy Bridgepoint Education (NYSE: BPI). Outside of Bridgepoint, I fully expect enrollments to be down across the board. Avoiding this sector altogether may put you at the top of the class.

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Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong. The Motley Fool owns shares of Bridgepoint Education. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.