What happened

After losing nearly 3% of their value on Wednesday, shares of hydrogen fuel cell stock Plug Power (NASDAQ:PLUG) resumed their decline on Thursday, closing the trading session down by 8.1%.

Simple red arrow declining stock chart on a white checked background

Image source: Getty Images.

So what

As you've probably heard by now, on Wednesday, would-be fuel-cell-truck company Nikola (NASDAQ:NKLA) announced a tie-up with CNH Industrial (NYSE:CNHI) to build out a hydrogen-fueling infrastructure across Germany, connecting hydrogen pipelines to fueling stations at which fuel-cell-powered vehicles could top off their tanks.

On the face of it, that sounds like something that ought to be good news for Plug. After all, Plug has a hydrogen-production business. It also builds fuel cells. Nikola stepping in as middleman to connect the one with the other would seem to be potentially helpful for Plug's business. But here's the thing:

Plug may not necessarily want Nikola's help.

Now what

To the contrary, as Plug described in a press release earlier this month announcing its application for a $520 million loan from the U.S. Department of Energy, its ultimate ambition is to "utilize its electrolyzer, liquefaction and distribution technologies to deploy [its own] network of zero-carbon hydrogen production facilities across the United States" -- and presumably in any other countries where it does business. More than that, in a presentation last year, Plug described its long-term ambition as a "vertical integration strategy," implying that ideally, it would like to own -- or establish its own partnerships with -- all parts of the hydrogen economy supply chain.  

Now, Nikola is trying to horn in on that action -- and Plug investors aren't pleased by the news one bit.

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