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 medical device specialist MAKO Surgical Corp. (MAKO.DL) surged 15% today after its quarterly results impressed Wall Street.

So what: The stock has plunged over the past year on concerns over slowing RIO systems sales, but today's second-quarter results -- revenue surged 19% while procedure revenue jumped 26% -- suggest that growth is back on track. So while MAKO's loss of $19.7 million missed estimates by a wide margin, stronger-than-expected demand should help management restore some investor confidence.

Now what: MAKO maintained its full-year guidance of 45-48 RIO systems sold and 13,500-14,500 MAKOplasty procedures performed.

"We are pleased that our programs implemented in the first quarter to drive utilization and system sales are beginning to show positive business results," said CEO Maurice Ferre. "Additionally, the recently released favorable data on both knee and hip MAKOplasty provides continuing support for the clinical value proposition of our procedures."

More importantly, with the stock still off about 30% from its 52-week highs even after today's surge, there might be plenty of upside left to buy into that bullishness.