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: Calix (NYSE: CALX) reported earnings last night, and shareholders are smiling today. At one point, shares of the broadband access equipment provider were up 10%, and even now they're holding onto the majority of their gains.

So what: "48% revenue growth." That's what's behind the share price surge. When CEO Carl Russo called the quarter "record-setting," he wasn't just whistling Dixie. Granted, earnings aren't looking quite so attractive. Calix reported losing $0.55 per share, GAAP, as a side effect of accounting for its absorption of Occam Networks.

Now what: As a result, Calix is not currently profitable. It's also not doing quite as well as we might like to see on the free cash flow front. After years of steadily improving cash production (or more accurately, steadily slower cash burn), Calix has recently come on hard times. Free cash flow dipped year over year in the first quarter, leaving the company with a grand total of $900,000 or so generated over the past 12-month period.

Investors seem to think this is enough "cash profit" to justify slapping an $840 million sticker price on the stock. But seeing that it values the company at 937 times free cash flow, I disagree.

Will Calix find a way to mend its cash flow "issues"? Keep following the story. Add Calix to your watchlist.

Fool contributor Rich Smith does not own shares of, nor is he short, Calix. The Motley Fool has a disclosure policy. Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.