What happened 

Shares of hydrogen fuel-cell company Plug Power Inc (PLUG -5.26%) jumped as much as 12% in trading on Wednesday after the company's chairman bought $426,000 worth of stock. At 3:25 p.m. EDT, shares were still up 11.6% for the day. 

So what

Chairman George McNamee purchased 200,000 shares of Plug Power stock for about $426,000 to increase his stake in the company to 661,131 shares. This happened within a window of time during which insiders can buy or sell stock, so we're seeing a big player do just that with Plug Power. 

An H2 symbol made from leaves on a floor.

Image source: Getty Images.

Insider acquisitions are generally seen as bullish signs for a company because insiders, especially at the chairman level, know exactly what's coming down the pipeline for a company. This could mean positive developments are ahead. 

Now what

Shares of Plug Power are actually hitting a new 52-week high, so this isn't exactly a value play by McNamee. This shouldn't entirely change investors' theses, but it's a data point to keep in mind when evaluating the stock. Long term, Plug Power's challenge is turning its potential into net income, and apparently, McNamee thinks that turnaround will happen soon.