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: Westport Innovations (WPRT 0.80%) stock advanced through the entire trading day, and jumped as much as 11% near 2:30 p.m. EDT before settling in with a better than 9% gain toward the end of trading. 

So what: Westport Innovations is set to release financial results for its fourth quarter and full year 2014 after market close today, with a conference call at 5 p.m. EDT to discuss the details. There's a good chance that the big price move today is simply the product of market speculation on the company's earnings report. 

Now what: Investors interested in the company should remember that this stock is very likely to be incredibly volatile for months to come, as the company struggles to establish growth. Frankly, the company's cash burn creates a serious risk, and there's not much likelihood that the company will reach profitability in the next year. Don't get me wrong -- that doesn't mean Westport is a guaranteed bad investment, just that investors should consider the risk when buying shares of the company. I own shares myself, but it's a very small position that I'm not likely to add to in the short term, barring a major change in the company's near-term prospects. 

I'll be doing an in-depth take on the company's earnings report once the release is out later this afternoon. Keep an eye here for that article once it's published.