Anyone heard of these guys? http://marathontradingllc.com/ I saw their office a few months back when I happened to be in their building. There seem to be a number of small shops like this in Philadelphia, like Bluefin, but they are very closed off. SIG seems to be the big game in town, but I'd like to see what the smaller places like Marathon have going on, but it really seems like you have to know someone. Anyone have any information about these guys or other non-SIG Philadelphia firms?
I just filled-out their contact form. I also checked into Bluefin, but despite the owner being from Philly, they don't list an office in Philly.