The moment you've all been waiting for. . .you can now make friends on the simExchange! But seriously, due to overwhelming user demand, you can now invite individual members to be your simExchange friends so that you can compare your leetness (trader performance) more directly.
Making friends on the simExchange is a simple process. A tutorial on making friends has been posted here.
Currently, the simExchange does not send out any kind of email notification that you have received a friend request. You will have to check the Pending Friends page. Hopefully you actually know a way to contact the person outside of the simExchange to let them know you've requested to be simExchange friends. Once you have become confirmed simExchange friends with someone, they will automatically appear in Your League rankings page. Try not to go overboard inviting random people because that defeats the point of having a friend specific rankings page. Duh!
More friend-enable features are coming soon!