Coming from the hedge fund world, $8.25M seems so small. It's amazing how much it can fund. What are the requirements for becoming part of the next YC round?

Coming from the hedge fund world, $8.25M seems so small. It's amazing how much it can fund. What are the requirements for becoming part of the next YC round? Do you have to know someone already involved with YC? Does YC only accept investors who are successful tech entrepreneurs? What about people who have the money through other means and are tech savvy? Can investors send a proxy who is qualified at helping out?