It's not uncommon for founders to sell their company. Even Paul Graham (who created Hacker News) has done it:
In 1996, Graham and Robert Morris founded Viaweb, the first application service provider (ASP). Viaweb's software, originally written mostly in Common Lisp, allowed users to make their own Internet stores. In the summer of 1998 Viaweb was sold to Yahoo! for 455,000 shares of Yahoo! stock, valued at $49.6 million.
You must be new here. Some useful info:
http://ycombinator.com
https://news.ycombinator.com/newsguidelines.html