Some career advice for all of you on Hacker News.
This advice may be two years too late, but may help someone just getting in now. The decision to leave a high-paying Wall Street firm is foolhardy and one that you will more than likely live to regret later. It would be much more prudent for you to stick around at a firm for 5-6 years, put away $500K-700K in cash, get some experience, make connections and then make your move. Otherwise, you'll probably end up stuck at a startup that is not really going anywhere anytime soon (maybe it will, but maybe it won't), and it will be too late to go back to Tier-1 firms to make some cash.
So the lesson for you young guys out there: Don't pull the trigger too soon IF YOU ARE ALREADY IN A MONEY EARNING JOB.
Wait it out for several years, build a small safety net, and stash away some capital for your entreupreneural endeavors a couple of years later.