What happened

Shares of all the major fuel cell stocks plummeted in early-morning trading Thursday, with Plug Power (PLUG -6.56%) and FuelCell Energy (FCEL -5.36%), for example, both falling roughly 13% before recovering and Bloom Energy (BE -2.95%) dropping 5.4%.

At the 11 a.m. mark, however, the worst of the panic seems to have passed. Yes, Plug stock is still down 4.7%, and FuelCell is off by 5.5% -- but Bloom Energy, at least, is back in the green -- and up 1.5%.

Red arrow goes down and green arrow goes up

Image source: Getty Images.

So what

It's no great mystery why fuel cells stocks stumbled this morning -- or why Bloom is recovering faster than most, either.

Crude oil prices started to slip late last week, falling in fits and starts all the way through Tuesday, and showing signs of declining periodically yesterday as well. This morning, they appeared to be headed for another fall, with WTI crude prices dipping briefly below $61.

Now, because hydrogen fuel cells can be considered an alternative-to-oil energy source, they're most competitive when oil prices are high and rising. The apparent downtrend in oil prices, however, sparked by concerns that oil stockpiles were rising, looked like it might upset one of the major attractions of alternative fuels -- sparking the fuel cell stock sell-off.    

Now what

Now, why did this trend just reverse? This morning, Houthi rebels in Yemen announced that they have successfully attacked an oil production facility of Saudi Aramco in gas-station-to-the-world Saudi Arabia. This sparked sudden fears of decreased oil production from Saudi Arabia in the short term, and perhaps continued supply shortages in the medium term if further attacks follow.  

These twin fears immediately sent oil prices shooting higher, and in late-morning trading the prices of both WTI crude and Brent crude oil are about 5% above what they were yesterday. This oil price action is giving companies that hawk alternatives to oil a share price reprieve.

Oh, and why is Bloom Energy in particular doing better than average today? On top of all the good news for fuel cell stocks generally, this morning Bloom stock got an upgrade from investment bank Raymond James. According to TheFly.com, RJ thinks the stock's "35% pullback" from its all-time high price, set on Feb. 8, gives investors a good chance of catching a bounce.

RJ couldn't have timed that call better if it tried.