What happened

Plug Power (PLUG) is in overdrive, rising another 20% (20.7%, to be precise) to close at $2.45 per share on Monday.

So what

"So what?" indeed. Last week, Plug Power exploded 73% higher in a single day, after e-tail giant Amazon.com (AMZN 0.78%) inked a deal to buy hydrogen power fuel cells from Plug to power its forklifts, and securing for Amazon the right to buy up to 23% of Plug Power's shares outstanding to boot. That makes Monday's rise seem more a molehill than a mountain by comparison -- but still, an extra 20% is an extra 20%.

Where did it the pop come from? That's hard to say. Last week, a pair of Wall Street analysts -- Cowen & Co. and FBR Capital -- raised their price targets in response to the Amazon deal. Both analysts said the deal made Plug Power a $3 stock, and FBR went so far as to say that a tie-up with Amazon could be "potentially ... transformative" for Plug, and that the deal's importance "cannot be overstated."

Wall drawing of big fish chasing little fish.

Plug Power investors' big hope -- that a bigger fish comes along and eats 'em. Image source: Getty Images.

Now what

Strangely, neither of those bullish investment banker reports did much to help Plug stock -- actually, the opposite, as the stock gave back some of last Wednesday's gains as opportunists sold into the rally and into the weekend. Today, though, Plug appears to be getting its mojo back.

Much as I'd like to say that the enthusiasm is deserved, though, it's hard to see much to like in Plug Power stock -- other than a faint hope that Amazon.com might eventually decide to buy it (as it bought out privately held robot-maker Kiva Systems in 2012. With Amazon as a customer or without, Plug Power still has negative profits for the past 12 months and projected continuing losses in the year to come. Experts posit that bringing on Amazon as a customer could double Plug's revenues, but even so, analysts quoted on S&P Global Market Intelligence still see little hope of the company earning a profit this year -- or next year, either.

So, yes. For the time being, Plug Power shareholders' best hope continues to be that Amazon ultimately decides to buy not just Plug products, but Plug Power itself.