What happened

Hydrogen fuel cell stock Plug Power (PLUG 0.56%) is down 7.8% as of 12:30 p.m. EDT Wednesday on no obvious news. In and of itself, though, that's not surprising.

So what

Plug stock hasn't been trading particularly rationally lately, falling on "good" news Monday, then rising on "bad" news yesterday. And yet, today's decline actually makes a bit more sense.

Consider: In yesterday's note, analysts at investment bank Piper Sandler dinged Plug stock on worries that while hydrogen fuel might have some attraction as a "green" energy source, still has to compete with wind, solar, geothermal, and hydrogen power -- all more widely accepted sources of renewable energy, and industries with established momentum.

While it's true, therefore, that Plug Power stock might benefit from the $2 trillion infrastructure plan currently working its way through Congress, it's also possible that this legislation will allocate the bulk of its "green money" to subsidizing solar, wind, and similar projects, rather than hydrogen fuel cells.

Cartoon fuel cell car on palm of hand putting out H2 bubbles as exhaust

Image source: Getty Images.

Now what

And that's what I think we're seeing today: Investors gauging the chances of the infrastructure bill being a big benefit to Plug or not -- and deciding today that "not" is the most likely answer.

Going forward, I'd expect that Plug Power stock will remain volatile as the prospects for hydrogen fuel cells winning subsidy money in the infrastructure bill ebb and flow. My advice to investors would therefore be to ignore this noise and wait on the sidelines until the bill's language is finalized. Only then will we have actual facts to invest upon.