Quote from yip1997:
Since the firm has 4 million BP, and if one trader longs 1 million value of GOOG, and another trader shorts 1 million of GOOG, the actual BP used is 0. Besides, you also can get cross margining benefit from the clearing firm.
I understood how it works, but I don't know if there are any regulation for running a prop trading frim or JBO.
Just a comment..."NO GOOGLE" LOL.
Yes, there a lots of regulations. You might look up FOCUS reports, and Net Capital Rules. Aggregation requirements (which is what you're referring to with the long short example). In our Firm, we are just one big account, which qualifies to have each trader treated independently for their P&L and long short rules. For example, if we didn't have the ability to "aggregate" then if one trader was short GE, and another one long, the long trader would have to mark Short Sale to get out (not hard since elimination of uptick rule, but the Clearing Firm must still borrow the short stock).
By having only one account to look it, it saves Goldman from having to monitor risk for each trader (which we do, obvioulsy), and that makes for a great long term relationship. Same Firm since 1978 (Spear Leeds bought by First Options and then sold back to Spear Leeds, and then bought by Goldman, whew! LOL).
Anyway, just sharing what I feel comfortable with to help others understand how it works.
All the best,
Don
edit: And, yes, TM has that right, capital use on both sides, unlike retail brokers who have long and shorts, but don't pay interest on the short stock sales (except maybe IB with a certain account balance).