It's tough to quantify. It's not just about the PB revenue itself. It's the fact that it's an entry point for a lot of institutional client activity that's nece

It's tough to quantify. It's not just about the PB revenue itself. It's the fact that it's an entry point for a lot of institutional client activity that's necessary for a lot of other lines of business. For example, investment banking is a very lucrative business. Let's say you're trying to win a big-ticket IPO. To run a credible IPO you need to be able to fill an order book of deep-pocketed, credible public equity investors. That requires having a relationship with these institutions. The primary way those relationships are built is through a prime brokerage business.