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.