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 Accuray (NASDAQ:ARAY) have dropped by 16% today after the company's after-hours earnings report  on Thursday revealed weaker full-year projections than investors had expected.

So what: Accuray's fiscal third quarter resulted in $97.5 million in revenue and a net loss of $0.04 per share. While the company's top line was weaker than Wall Street's expectations for $102.7 million, its loss per share was narrower  than the $0.06 loss per share Wall Street had expected.

However, it was Accuray's updated full-year guidance that seems to have sent investors scurrying. The radiation therapy specialist now expects its total revenue for the 2015 fiscal year to range from $375 million to $385 million, down from an earlier range of $390 million to $410 million and well below Wall Street's consensus estimate of $394.2 million in full-year revenue. The company's adjusted EBITDA guidance was also slashed from an earlier range of $18 million to $27 million to a weaker range of $13 million to $16 million.

Now what: Accuray's new guidance ranges compare rather unfavorably to its 2014  fiscal year, which produced $369.4 million in revenue and $13.3 million in adjusted EBITDA. At the high end of its guidance ranges, Accuray would only improve its top line by 4% over last year's result. While EBITDA might grow by up to 20%, it might even shrink on a year-over-year basis if Accuray can only reach the low end of its guidance range.

Today's drop ruins what had been a generally flat 52 weeks of trading for Accuray's stock, and investors are now holding a 14% loss for the past year. Since Accuray does not seem poised to outgrow its cash-bleeding ways just yet, it's hard to call that drop a buying opportunity. I'd wait for a clearer picture of growth and profitability before moving into this downtrodden stock.