this means almost nothing IMHO as they are facilitating customer trades (e.g. buy IBM bond at 100 from person A and sell at 100.05 to customer B). They are not prop trading profitably 200 days in a row.
looked at this thread that the guy put up. If his PnLs are real...i would venture to say this guy is a pretty good trader. come on people, buy double bottoms and short double tops!