Businessman and billionaire Elon Musk has a penchant for the letter "X". One of his Tesla vehicles is called "Model X," his commercial spaceflight company is called "SpaceX" and now his newly acquired domain is X.com.

The website is not entirely new. Musk used to own it but repurchased it for some mysterious reasons that he's been teasing about in the last few days. The businessman posted about it on his Twitter account on July 14.

"Excited to announce the launch of http://x.com! It's a little verbose right now, but that will be fixed tomorrow," Tesla and SpaceX CEO Elon Musk said.

New website

Musk looks like he still has time on his hands. He intends to launch another venture despite juggling his responsibilities with his companies Tesla, SpaceX and Boring Company. However, not many details have yet been revealed but the name of the website consists only of the letter "X."

He used to own X.com during the earlier days of PayPal. According to Gizmodo, Musk lost the domain when the company went public. His reacquisition of the website is quite controversial. Experts say it must have cost a fortune today and could have been sold for a staggering eight figure price but no amount had been disclosed.

Single letter domains

What makes the website more expensive is that single-letter domains are no longer available today.

This came after Internet Corporation for Assigned Names and Numbers (ICANN) decided in 1993 that single-letter domain names could not be used anymore. The only exceptions to the rule are the existing six letters used as website names at the time of the ruling including "q.com," "q.net," "x.com," "z.com" and "i.net."

Although there were recent talks of freeing single-letter domain names, it did not materialize making the existing ones more expensive.

Reports say that although some single-letter domain exists today, like t.com for Twitter and m.me for Facebook Messenger, only "x.com" uses the most coveted .com.

In an update, Musk said in a Tweet that it is "fixed now," but upon visiting the web page, it only contains a letter x in the upper left corner. This means Musk must have been fixing something internal and not the contents of the website just yet.

No one really knows for sure what the businessman is planning to do. One thing is for sure, whatever he launches next it is going to stir public attention and opinion. Recently, he started his Boring Company that plans to build a network of underground tunnels to ease the traffic in LA.