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 company DexCom (NASDAQ:DXCM) climbed 10% today after its quarterly results topped Wall Street expectations.

So what: DexCom's fourth-quarter beat was so wide -- loss of $0.12 per share on revenue of $33.2 million, versus the consensus loss of $0.18 and $31.1 million -- that Wall Street has no choice but to raise its valuation estimates yet again. In fact, product gross margin for the quarter expanded to 54% from 49% in the year-ago period, giving investors plenty of optimism about its path to profitability.

Now what: For the full-year 2013, management reiterated its product revenue guidance of $120 million-$130 million.

"Our pipeline of new patient opportunities remains robust," said CEO Terry Gregg in a conference call with analysts. "Call volumes into customer service remain strong, and in spite of typical first quarter seasonality, first quarter sales through late February have been solid."

Of course, with the stock hitting a new 52-week high today and sporting a lofty price-to-sales of 12, much of that operating momentum might already be baked into the price.