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 mortgage industry software specialist Ellie Mae (NYSE:ELLI) plunged 20% this morning after its quarterly results and outlook disappointed Wall Street.

So what: The stock has skyrocketed over the past two years on better-than-expected growth, but today's thrid-quarter results -- EPS fell by half even as revenue jumped 20% -- coupled with downbeat guidance reignites concerns over sluggish demand going forward. In fact, Ellie Mae said that total mortgage origination volume for 2013 is expected to decrease 14% year-over-year to $1.8 trillion, suggesting plenty of downside risk to its upcoming quarters.

Now what: Management now sees fourth-quarter EPS of $0.17-$0.18 on revenue of $29.5 million-$30.5 million, versus the consensus of $0.24 and $32.5 million. "We are intensifying our marketing efforts, reinforcing our implementation and customer support teams and investing in research and development," CEO Sig Anderman reassured investors. "We remain confident that this will strengthen our competitive advantage and bring sustainable, long term value for our customers and our stockholders." More important, with Ellie Mae now off about 30% from its 52-week highs and trading at a PEG around 1, Mr. Market might finally be providing a window to buy into that long-term bullishness.