What happened

Down 15% one day. Up 15% another. I'll give FuelCell Energy (FCEL -2.54%) this much: Investing in this stock is anything but boring!

Today, FuelCell stock is bouncing back from a 15% sell-off Monday, having recovered most of its losses with a 15.6% gain as of 10:50 a.m. EST. (Note to investors and math geeks: A 15% decline followed by a 15% rise still leaves you sitting at a lower stock price than you started out at.)

Of course, this still leaves us scratching our heads and wondering: Why exactly is FuelCell going back up today, even if not quite to its price at the end of last week?

Arrow angles up on a green stock chart

Image source: Getty Images.

So what

It's an excellent question -- because there's literally no good news happening at FuelCell today that could explain the stock's sudden rebound. No analyst upgrades. No price target hikes. No positive PR coming out of the company itself.

At best, what we've got is the fact that in a couple of days, FuelCell's rivals Ballard Power (BLDP -1.50%) and Plug Power (PLUG -2.75%) are due to report their own quarterly earnings. Conceivably, good news out of one (or both?) of those companies could have a beneficial knock-on effect and revive investor hopes for FuelCell stock.

Now what

Maybe. The fact remains, though, that just like FuelCell, Ballard and Plug Power stocks remain firmly unprofitable. In fact, none of these three alternative energy companies have earned any profit at all for the past decade.

Call me a skeptic, but I don't expect that to change when Ballard and Plug Power report. On the contrary, if I were a betting man, I'd bet on today's FuelCell stock gains melting away sooner rather than later.