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: Riverbed (Nasdaq: RVBD) shares jumped 16% in early Friday trading, after the company "beat earnings" by a mile. The company posted twice as much profit in Q3 2010 as it earned one year before -- and reported a 2-for-1 stock split to boot.

So What: As far as stock splits go, you know the Foolish position -- this is a non-event. But Riverbed's profits are real, and even bigger than they appear. Actual free cash flow produced year to date hit $105.4 million, or nearly five times reported net income.

Now What: If Riverbed keeps earning at its current rate, the company's price-to-free cash flow ratio of 28 looks reasonable, given analyst projections for 25%-plus long-term growth. This makes the stock a fair value today, but the better play might be to take a position in F5 Networks (Nasdaq: FFIV) or Cisco (Nasdaq: CSCO) ahead of their earnings announcements. F5 reports next week; Cisco early next month. If either or both perform as well as Riverbed and Juniper (Nasdaq: JNPR)  just did, investors will have Riverbed to thank for the early hint.

Want to keep a closer eye on Riverbed Technology? Add it to your watchlist.