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 BroadSoft (NASDAQ: BSFT) closed up 17.2% Monday after the company announced better-than-expected first-quarter results.

So what: Quarterly revenue rose 27% year over year to $55.7 million, which translated to adjusted net income of $7.3 million, or $0.24 per diluted share. Analysts, on average, were expecting BroadSoft to achieve adjusted earnings of only $0.17 per share on sales of $54.3 million.

"We believe this was a result of both positive market demand trends," said BroadSoft CEO Michael Tessler, "as well as our execution against our strategic focus areas of driving adoption of true unified communications, broadening our cloud delivery and promoting end-user sell-through. We look forward to continuing this momentum through the remainder of 2015."

Now what: For the current quarter, BroadSoft expects revenue of $59 million to $64 million, and adjusted earnings per diluted share of $0.24 to $0.36. Both ranges were within analysts' models, which called for second-quarter earnings and revenue of $0.32 per share and $61.5 million, respectively.

Finally for the full year 2015, BroadSoft sees revenue of $260 million to $268 million, and adjusted earnings per share of $1.42 to $1.66. The mid-point of both ranges sits just above Wall Street's expectations for 2015 earnings of $1.53 per share, and revenue of $263.2 million.

All things considered, given BroadSoft's outperformance both in Q1 and for guidance, it's no surprise the market is bidding shares up today. But even then, with the promise of sustained momentum and BroadSoft stock currently trading at a reasonable 19 times next year's expected earnings, I would be equally unsurprised if the stock didn't continue to rally from here.