To me it seems that there may exist some arena Chats in which players prearange positions at payout time. I think this is extremely unfair against players that do not participate in such actions and also a breach against code of conduct.
I ask Capital Games to issue an official statement against win trading.
Beside this I suggest to mix top 50 average arena players of each server through every one or two months. This would change the player base at the top of each server regularly so such chats can not build up for longer times. There could be server categories that prevent a mix of old and new players.