Because they split their volume up between tons of fulfillment centers/counter parties. I wrote a framework that did this. It was designed to allow obfuscation.
So it seems like from many of the responses, I should stick to the lone wolf route. I get it from the pure numbers perspective, which is probably the main factor right now. But what about the possible networking? Is there even networking when it comes to prop firms? Keep in mind I have zero experience trading with a firm, so yes I'm aware that I sound like a total newbie on this. No opportunities to transition to something else finance related outside the prop trading industry after you leave or "retire" from trading? What if I somehow get really big and find new and extremely liquid edges and want to start a hedge fund (yes, unrealistic, but what if...)? Wouldn't at least having experience with prop firms and knowing people with access to lots of capital be better than trading for yourself at home? Or is a hedge fund something that only an ivy grad with rich family and friends can pull off?
Reminds me of a line from "The Hunt for Red October"... "Could you launch an ICBM horizontally?" "Sure. Why would you want to?" In the same vein, why would you want to join a prop firm and mess up your line of thought when you are doing so well on your own?
I strongly disagree. Take the offer. By all means, hedge your bet -- keep your Wisconson apartment, rent temporary in NYC (outer boroughs still [relatively] cheap and you can use subway time to wake up fully), and if it doesn't work out you just return to Wisconsin and pick up where you left off. Yes. You'll have an order-of-magnitude harder time of it as a small private trader in Wisconsin with no industry contacts whatsoever. As a private trader you'll with no industry network, you'd find it nearly impossible to raise enough outside trading capital (probably 10mm absolute minimum) to make a hedge fund viable. I repeat. Take the offer.
But he is not having a hard time at all as a private individual, doing it on his own...? Wouldn't going the prop route add complications?
Well, ajm, you certainly have some things to think about now. You brought home $190K last year, and a bunch more money in the past couple of years. Groovy. You are at a crossroad now I guess. The choice to you will become clear soon enough. Just never live with regrets.
There is a bunch of questions to answer first: 1. how does your strategy scale with size (e.g. would you be able to accomodate 10x the size)? 2. do you have other ideas that you want to research and that require institutional support? 3. are they going to give you any support/development help? 4. are they providing infrastructure that you need to run your strategies? most importantly, 5. what is the end goal? and finally 6. did you like the people you met? If 5 is "I want to run my own large(er) business" or "i want to make money at a larger scale working for someone else", your best bet is to take the job - worst case you will have some connections. 1 - 4 will give you a sense of the quality of the opportunity; there are a lot of prop shops in the NYC and if you have interesting ideas you can find opportunities fairly easily. #6 is probably key - working for assholes in a risk-taking role is a very sad space to be (trust me, I know that situation well).