What happened

Shares of fuel cell pioneer Plug Power (PLUG -5.25%) were on the upswing Monday, rising 4% through 11:35 a.m. EDT today. Curiously, the reason that the stock is rising may have little to do with Plug at all.

Black and white drawing of an electric plug and a connector

Image source: Getty Images.

So what

There seemed to be little news on Plug Power this morning. But there is a new analyst upgrade for Plug's alternative energy rival Ballard Power (BLDP -2.23%), which this morning received an upgrade to speculative buy from TD Securities.

Ballard is preparing to hold an investors day, says TD in a note covered by TheFly.com, and the analyst is looking to see new information on the green stimulus programs in several countries, in addition to several other potential catalysts. Logically, though, such stimulus programs could benefit companies other than just Ballard.

Now what

Indeed, it seems that any stimulus programs that deliver more cash to Ballard, with its $116.5-million-a-year business, would benefit Plug (with $260 million in sales annually) even more. In the absence of any other news that might be lifting Plug stock, I suspect what we're seeing today is Plug benefiting from an analyst note that didn't even mention it.