What happened

Shares of Luminar Technologies (NASDAQ:LAZR) were trading higher on Tuesday morning after some images of a Tesla (NASDAQ:TSLA) Model Y equipped with what appear to be Luminar lidar sensors made the rounds on social media.

As of 11:30 a.m. EDT today, Luminar's shares were up about 7.3% from Monday's closing price.

So what

Here's what happened. First, this tweet from Monday night got some notice.

Then this follow-up from another user appeared on Tuesday morning.

 

The implication, if it isn't clear, is that Tesla might be testing Luminar's sensors. If true, that would be big news for a couple of reasons. First, Tesla would be a great customer for Luminar. And second, it would suggest that Tesla CEO Elon Musk, who has famously maintained that Tesla will be able to make self-driving vehicles without lidar sensors, has had a change of heart.

That appears to be why Luminar's stock was soaring on Tuesday morning. But was it a false alarm? 

A Volvo test vehicle with Luminar sensors on a roof rack.

This photo from Luminar shows its Hydra lidar system on a Volvo test vehicle. Image source: Luminar Technologies.

Now what

The great thing about Twitter is that if you're patient, sometimes actual experts will weigh in. In this case, a couple of engineers with experience in automotive sensors said that the sensor array suggests that Tesla is using this vehicle to train its machine-vision systems, or what is called "ground-truth" testing.

This isn't the first time that a Tesla-owned Tesla with lidar sensors has been spotted doing ground-truth testing; the fact that this vehicle is using Luminar units is interesting, but it probably doesn't tell us much about either company's plans. 

Long story short: There are good reasons why auto investors might consider buying Luminar's stock. But based on what we know now, this shouldn't be one of them. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.