Among the 1% there exists multiple deep and consistent insider networks where stock tips and wealth creation ideas are exchanged. So the 1% crowd thrives from being in that position.
First - there is tons of 'insider trading' going on. It's easy to do, and hard to prove.
Second - though maybe not 'insider' in the illegal sense - but once you have a lot of wealth, you have access to information and systems that others do not.
Warren Buffet made huge bank of a loan to Goldman during the crises. He was one of the few to have the cash and the reputation. Buffet can take advantage of so many situations that very few others can. So that's a lot of leverage.
I'm not saying anything against them, but big finance is an 'insiders game'.