I guess Elon Musk will sweat to get X trademarked! Elon Musk would likely face challenges in trademarking a single letter of the English alphabet like "X" because it is a common and widely used symbol. Trademarks are typically granted for unique and distinctive symbols, words, or logos that can be associated with a specific brand or product. Common letters or symbols are generally not eligible for trademark protection on their own. However, if "X" were used in a unique and distinctive way in combination with other elements to create a recognizable brand or logo, it might be possible to trademark that specific design or combination.

https://hoperite.com/Literature/ElonMusk/#wbb1