I'm a Quantopian and Python newbie. Then again, I guess that Quantopian is a newbie too! I think that it is an excellent concept and hope that it succeeds. I've been actively trading low liquidity exchange traded securities as a retail trader for a number of years. I was just looking for the tools to speed up development of new strategies and to automate my trading. I wandered across Quantopian and it seems like it might be a good fit.