What happened

For a sixth straight day, shares of electric vehicle (EV) star Tesla (TSLA 12.06%) drove higher on Tuesday, up 2.5% as of 12:45 p.m. ET. CEO Elon Musk might be personally responsible for that with a tweet yesterday.

Stock up glowing green arrow climbs on a stock screen.

Image source: Getty Images.

So what

In a grammatically challenged tweet yesterday evening, Musk said the "Main Tesla subjects" [whatever those are], will be scaling to extreme size, which is needed to shift humanity away from fossil fuels, and AI."
 

It's not entirely clear what Musk was trying to say with this tweet (and since Tesla deleted its public relations department two years ago, it's not easy to get clarification). On the one hand, shifting "humanity away from fossil fuels" through the use of EVs and solar power panels has long been an ambition of Musk -- no mystery there.

But is he also saying he wants to shift humanity away from artificial intelligence, too -- a technology he's expressed serious reservations about in the past?

Or is he rather hoping to use AI in order to accelerate the shift away from fossil fuels -- for example, through continuous improvement of Teslas' full self-driving capability? 

I suspect it's the latter, but it's not entirely clear.

Now what

What is clear is that last week, Musk told investors in another tweet that he is "working on Master Plan Part 3," which implies that something big is in the works, and now we know that whatever that something will be, Musk considers it to be of "extreme size."

Whatever he's up to, that sure sounds like something that could move the needle on Tesla stock. And indeed, we're already seeing that needle shiver today. Stay tuned for further details -- whenever Musk gets around to sharing them.