What happened

Gas prices continue to surge, and electric car stocks remain red hot on Tuesday.

As of 11:05 a.m. ET, shares of Chinese electric automaker Nio (NIO -0.48%) had tacked on yet another 1%, while Tesla (TSLA 4.96%) stock was up 2.1%, and Nikola (NKLA -3.23%) -- surprise! -- was leading the pack higher with a 9.3% gain.

2 electric cars plugged into a charger side by side at dusk.

Image source: Getty Images.

So what

What news is driving investors' decisions Tuesday? The answer is kind of curious, I have to admit -- because the news actually isn't all good.

On the one hand, yes, rising gas prices have people thinking that now's a great time to buy both electric cars and electric car stocks. According to the latest data from GasBuddy.com, gas prices have topped $5 a gallon in California, are getting close to $5 in Hawaii, and have already passed $4 in much of the Pacific Northwest and Northeast. Meanwhile, Twitter is starting to fill up with posts from Tesla-owners bragging about how much cheaper it is to "fill up" their vehicles with electrons rather than hydrocarbons.

At the same time, though, worries are starting to emerge about how many electric car companies can really be winners in a world where some of the key components needed to build those cars seem to be in short supply.

Now what

Consider: In a note covered by TheFly.com Tuesday morning, investment banker Morgan Stanley says it is "increasingly concerned" by an "ever widening gap" between car companies' promises to produce X number of electric cars annually ... and the production capacity of battery makers to make all the batteries needed to run them.

In this regard, Morgan Stanley is most confident that Tesla and certain Chinese automakers (read: "Nio") are "locking up" sufficient manufacturing capacity to ensure they will be able to hit their production targets. But every battery that goes into a Tesla or Nio is one that won't be available to power an electric car from Ford, for example -- or an electric truck from Nikola, for that matter. Accordingly, Morgan Stanley is cautioning investors to apply a "generous" discount to any production promises that companies not named Tesla or Nio make -- and assume they will not, in fact, hit the numbers they are promising.

Also worth keeping in mind: The potential for interruptions in supplies of raw materials needed to build batteries -- nickel from Russia in particular -- has some analysts predicting that prices of electric cars will be going up. Morgan Stanley estimates that nickel shortages alone might raise the cost of an average electric car by as much as $1,000.  

Long story short: Electric cars might well become more popular in an era of high gasoline prices. They might also become more expensive, depressing demand, keeping sales in check, and squeezing profit margins for the companies that manufacture them.