Equities and Debt Market Makers

[JasonHunt]

Hi, I'm trying to compile a list of companies who focus on market making with equities or bonds. Actually, they can trade any sort of assets which provide non speculative growth potential. It doesn't need to be their primary business, but I would prefer if it's a farely large part of their strategy, so it's not at risk of being phased out any time soon. I appreciate any input you can offer. Thanks.