Also of note is that the stock ticker symbol "X" is, for whatever reason, US Steel [0]. If Elon ever takes his X Company public, I bet there will be a lot of erroneous buys of US Steel, similar to what happened when Twitter originally went public [1] (an unrelated penny stock with the ticker symbol TWTRQ surged), or when an unrelated company with the ticker symbol ZOOM surged when people started buying Zoom videoconferencing stock (ticker symbol ZM) at the start of the pandemic [2].
IIRC the X came from the 1980s when it branched out into energy, bought Marathon Oil, and reorganized into an umbrella company named "USX" in which the US Steel part became just a subsidiary. They exited that in 2001 but apparently? kept the symbol.
"Mr. Roderick explained that for months the company had considered more than 200 new names, ranging from U.S.S.A. and Amcor to Maxus. U.S.X. was selected, he said, because ''it had a continuity from the U.S. part.'' He added that X had been the company's symbol on the New York Stock Exchange since 1924. "
There's no obvious connection between X and US Steel - maybe somebody just thought X sounded cool?
[0] https://www.google.com/finance/quote/X:NYSE
[1] https://www.forbes.com/sites/steveschaefer/2013/10/08/after-...
[2] https://www.yahoo.com/video/confusion-over-stock-names-zoom-...