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 Plug Power Inc (NASDAQ:PLUG) jumped 45% today after announcing a partnership with FedEx Corporation (NYSE:FDX).

So what: Plug Power will develop hydrogen fuel cell range extenders for 20 FedEx Express electric delivery trucks, which will about double their range to about 160 miles. The $3 million project is funded by the U.S. Department of Energy.  

Now what: This is a big win but it also needs to be put in context. This is for only 20 vehicles and is a test program, not a huge order from FedEx. The $420 million market cap for Plug Power is awfully expensive for a company with just $24.5 million in revenue over the past year. I like the opportunity, but this stock is just too expensive to bet on right now.

Fool contributor Travis Hoium has no position in any stocks mentioned. The Motley Fool recommends FedEx. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.