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 ARRIS Group (NASDAQ:ARRS) are holding to a near-11% rise today after popping to an opening-bell gain of about 18% following the broadband network specialist's double beat on its fiscal first-quarter earnings last night.

So what: ARRIS reported revenue of $1.23 billion -- a monster 246.4% year-over-year improvement -- and adjusted earnings of $0.47 per share. Wall Street's optimistic consensus had called for revenue of $1.19 billion and earnings of $0.45 per share. ARRIS now expects to generate revenue of $1.41 billion to $1.45 billion for the second quarter, with earnings per share ranging from $0.64 to $0.70. These guidance ranges are both massively above Wall Street's consensus for "only" $1.21 billion in revenue and $0.50 in EPS.

Now what: ARRIS shares have been on an absolute tear over the last few months, and have already gained about 65% after today's pop. There's a very good reason for that, as ARRIS has become very good at generating free cash flow despite posting rather erratic generally accepted accounting principles net income over the past few years. Since the end of 2012, its trailing 12-month free cash flow is up over 650%, and even though GAAP EPS is negligible at the moment, ARRIS' price-to-free-cash flow ratio was a microscopic 8.4 before accounting for last night's report. This huge beat and even larger guidance overachievement certainly merits a deeper dive, as ARRIS could have a lot of growth left if it can keep up this pace.

Alex Planes has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.