Judging by the replies, it seems like the concept of direct market access is obsolete and any advantages there were 10 years ago are now mostly dead. Looks like the CME/CFTC has cracked down on risk control and there's no way I'm going to trade 10,000 ES contracts intraday with only $500k of capital. Unless, I do self-clearing, start my own clearing firm or something along those lines. I wonder what's the minimum amount of capital required to do that. I've always heard stories about how floor traders put up very little capital but were able to trade huge size intraday. And with regards to latency reduction, these days there's very little difference between pre-trade risk control (Rithmic/CQG/TT) and post-trade risk control, so DMA is not worth the cost unless you're doing high frequency stuff. I still don't get exactly how the CME is doing risk control. I thought the CME could only do risk control on a per-FCM basis, not an individual's account in the FCM. If the FCM has 20,000 client accounts, can the FCM create 20,000 risk control accounts with the CME, one for each client? ...oh wait, I think I got it, the CME charges a large fee for each account/ID/iLink created?? ...So, I guess the business models of Rithmic/CQG/TT are safe after all because they charge less than the CME.