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 Blucora Inc (NASDAQ:BCOR) are trading 9% lower today after plunging to an early loss of over 13%. Investors are not happy that the company has produced weak guidance for the second quarter, despite the fact that it came through with decent earnings.

So what: Blucora reported its first-quarter results last night, which showed revenue of $216.2 million -- a 31% year-over-year gain -- and earnings of $1.12 per share. Analysts had expected $217.9 million in revenue and $1.03 in EPS, which means that Blucora beat the bottom-line estimate but fell a little short on the top line.

However, Blucora's guidance for the upcoming second quarter is what's gotten investors freaked out: the company now expects $135 million to $145.5 million in revenue, against Wall Street expectations of $163.4 million, and projects that its EPS will range from $0.46 to $0.53, which again falls far short of Wall Street's $0.64 EPS expectation.

Now what: Blucora shareholders have already suffered a gut-wrenching drop this year -- the stock had nearly quadrupled since the start of 2011 before crashing to a 40% loss in 2014. However, its forward guidance is pretty darn weak, as Blucora projected higher EPS  for second quarter of last year at a range of $0.51 to $0.55, despite expecting lower revenue than it does this time around.

Dwindling margins are never good news, but it's also worth noting that Blucora's price-to-free-cash-flow ratio is lower than it's ever been at 8.4, which indicates that focusing solely on EPS might not be the best way to assess this stock. Do a little digging today and you might find that this abandoned former growth stock could become a winner once again.