most established securities houses have their corporate finance department, which help corporate clients raise funds from the equity capital markets. of course when it comes to ibanking, traditional banks do have their distinct advantage over securities house since they are blessed with a deeper pocket. But, i am afraid to say, if you always carry things onto your balance sheet, you are far from being a good ibank.

another matter of fact is that most bulge bracket/first tier ibanks, e.g. GS, ML, MS, SSB, Lehmen, etc, started as securities houses.