Elon Musk, who runs electric car maker Tesla, aerospace and space transportation company SpaceX, brain-machine interface firm Neuralink and The Boring Company (that builds underground tunnels), thinks that creating a holding company above all the four firms is a "good idea".

Responding to a Twitter follower who asked on Wednesday about Musk to create a parent company called 'X" for all the four firms to "ensure human survival and progress".

Musk responded" "Good idea".

The follower named David Lee added in a tweet: "X is mostly because Elon already owns the http://x.com domain name and it's a decent name".

The best example for Musk to follow is Alphabet, which is the parent company of Google and several Google subsidiaries.

On August 10, 2015, Google announced plans to create a new public holding company named Alphabet Inc.

In his announcement, then Google CEO Larry Page described the planned holding company as follows: "Alphabet is mostly a collection of companies. The largest of which, of course, is Google.

"This newer Google is a bit slimmed down, with the companies that are pretty far afield of our main internet products contained in Alphabet instead. Fundamentally, we believe this allows us more management scale, as we can run things independently that aren't very related".

However, according to the Verge, the big difference is SpaceX, Neuralink, and The Boring Company are all separate entities that exist outside of Tesla.

"Create a Tesla subsidiary called 'X,' create a merger entity underneath that, and then combine the merger entity with Tesla. Tesla shareholders transform into equivalent shareholders of X, deal done," the report said.

Combining the four companies under "X" could help Musk further sell his futurist vision.