The answer to this question is yes, there are still thousands of unregistered 5-letter domains left. The true question is are there any good 5-letter domains left? For example, I just went to Godaddy and randomly typed five characters on the keyboard, and iughl.com is now available to register. Would you start a new business on that domain? For a 5-letter domain to have any value it should be pronounceable easy to remember and spell. It must be a .com. There are hundreds of different extensions but .com is still king. When it comes to the worth of a 5-letter domain a dictionary word could sell in the millions. According to namebio.com voice.com sold for $30,000,000, it still holds the record for the highest reported sale. Every week non-dictionary names sell for $500-$10,000. I write a blog with the top 10 5-letter non-dictionary domains sold every week.
It is possible to open a domain register and still register a decent LLLLL but it can be quite time-consuming. There are many marketplaces selling 5-letter domains but as far as I know, this is the only website that specializes in only 5 letter .coms.
Check out our available 5 letter .com domains