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 online education specialist K12 (NYSE: LRN) were getting an F from investors today as shares fell as much as 15% in reaction to the company's quarterly earnings report.

So what: On an absolute basis, K12's results for the quarter looked really darn good. Revenue for the quarter shot up 43% to $193 million. Some of that growth came from acquisitions, but organic growth was a still-strong 26%. On the bottom line, earnings per share soared 71% thanks to the revenue growth and a lower tax rate, offset somewhat by a higher share count.

Unfortunately, Wall Street was looking for even better results. Per-share profit estimates from analysts averaged $0.23. The bottom-line miss extends the company's streak of whiffing on Wall Street's estimates.

Now what: On the bright side, the company's projection for full-year revenue (K12's fiscal year ends in June) is $680 million, above the current average analyst expectation of $671 million. However, revenue wasn't the issue this quarter -- in fact, K12's revenue for the current quarter topped expectations. What investors will want to keep an eye on is profitability, as analysts seem to be expecting margins to expand faster than they are. The company didn't provide a view about full-year profit because of "potential variability in depreciation and amortization."

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