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 Inteliquent (NASDAQ:IQNT) have gained nearly 13% today after the company released its fiscal first-quarter financials that showed a double beat of Wall Street analysts' revenue and EPS estimates.

So what: Inteliquent reported first quarter revenue of $56.2 million and net income of $9.2 million, which works out to earnings of $0.29 per share based on the company's current share count. Analysts had anticipated revenue of $50.6 million and $0.23 in EPS.

The company also updated its full-year guidance, which now projects revenue in a range of $210 million to $220 million -- well ahead of Wall Street's $203.7 million consensus -- and anticipates adjusted EBITDA to range from $68 million to $72 million. First-quarter adjusted EBITDA was $20.2 million, so if net income has a similar relationship to adjusted EBITDA for the full year, we can project a (very) rough net income guidance range of $31 million to $32.8 million, or $0.96 to $1.02 in EPS. That guidance range also comes in well above Wall Street's consensus estimate of $0.90 in EPS for the year.

Now what: Inteliquent shareholders have enjoyed a monster surge since early 2013, as shares have already gained nearly 700% over the past 16 months. But it's worth noting that the company remains incredibly inexpensive on both a P/E and a price-to-free-cash-flow basis, as its P/E is only 9 and its P/FCF ratio is just 11. Looking ahead, this sort of guidance would moderate the company's P/E quite a bit, to a more reasonable 15.7, but that's hardly nosebleed territory, either.

One thing investors need to watch is the company's difficulty improving its top line, which finished at $222 million for 2013 -- and that figure was 17% smaller than its annual revenue for 2011. Inteliquent is a very intriguing stock, and it's certainly worth digging into, but investors should do their homework before jumping in.