What happened

As Americans head to the polls, and Democratic presidential candidate and green energy aficionado Joe Biden continues to hold a polling lead over President Donald Trump, Tuesday looks like it's going to be a strong day for renewable-energy stocks. In early trading, shares of fuel cell stock Plug Power (PLUG -6.95%), its rival Bloom Energy (BE -1.93%), and lithium mining stock Piedmont Lithium (PLL) all topped 10% gains.

As of 10:40 a.m. EST, Piedmont in particular is gaining strength, up 15.8%, while Bloom is in second place with an 11.6% gain, and Plug Power is up a solid 9.5%.

Three colorful arrows racing straight up on a black background

Image source: Getty Images.

So what

Why are all of these stocks moving higher? Generally speaking, optimism about Joe Biden's promise to spend $1.7 trillion on renewable energy infrastructure (if he wins) undergirds much of the enthusiasm. Curiously, though, there's also a bit of actual positive news related to Plug Power.

As TheFly.com reports, privately owned hedge fund sponsor D.E. Shaw yesterday made a filing indicating that it has taken a 5% ownership stake in Plug Power stock.  

Now what

D.E. Shaw's filing confirms it now owns 20.3 million shares of Plug Power stock. It doesn't say why D.E. Shaw bought the stock, or what it plans to do with the shares (such as agitate for restructuring or acquisition, payment of dividends, or something similar).

And really, someone had to own the stock. If not D.E. Shaw, it would have been someone else.

Still, investors seem to be viewing the size of the reported stake as a positive for Plug (i.e. someone is making a big bet on renewable energy on election day, and a big bet on Plug Power and fuel cells in particular). I guess that's a positive. I guess it's a reason to get a bit more optimistic about Plug, about Bloom, and maybe about Piedmont Energy, too.

I'd just personally be a bit more confident about these stocks if any one of them had earned at least a penny's worth of profit in the last 10 years -- but they haven't.