https://en.wikipedia.org/wiki/Elon_Musk
https://youtu.be/zIwLWfaAg-8?t=36m4s
https://www.youtube.com/watch?v=sytrrdOPYzA
He is clearly Gamma NT. I have heard LIE for him and that sounds about right. His nervousness matches an ILI but he is a bit more expressive, and even LIEs are nervous and can be self-deprecating. He appears to be optimistic about the future, and seems to think a lot about things that could go wrong, technologies that don't work, technologies that could be improved, the rate of improvement in different technologies, and appears to have a good understanding of logistics and how economic processes function, the way the world works (Te)--how he mentions at the end of the first vid that technology does not always improve, if anything its natural tendency is to decay.
Listening to the way he discusses how he sees time in the first video was very interesting for me. I relate to some aspects of how he describes time--probabilities, branching timelines, identifying inevitabilities, and foreseeing potential disaster (i.e. dead ends)--but he is able to see apply it to technology and industry at a very large scale (in terms of rates of production, knowledge generation, etc.) and he seems to be able to very flexibly move from discussing the timeline for a project to discussing the trends of industry and humanity as a whole. He also seems to hedge and prefer non-absolute time estimates for projects, but when he does give them they have been shown to be optimistic. I sometimes get the feeling he knows it will might longer than he says.
When he discussed watching the Falcon Heavy launch & landing, he said he saw everything that could go wrong and was kind of surprised everything worked.
Anyways, be curious to see what y'all think about him from a Socionics PoV.