Prime Broker (PB)

A prime broker sits at the center of a hedge fund’s trading infrastructure. It holds the fund’s long positions, lends securities for short sales, finances leveraged positions through margin lending, clears trades executed with other brokers (give-ups), and produces consolidated daily position, cash and P&L reports. Many funds use two or more prime brokers to spread counterparty risk.

The relationship is governed by a prime brokerage agreement, typically alongside an ISDA for synthetic exposure such as swaps and CFDs. Assets held as collateral can often be rehypothecated by the prime broker up to agreed limits, which matters for counterparty exposure analysis.

For fund operations, the prime broker statement is a primary source for daily position reconciliation and cash reconciliation. Common breaks include financing and stock-borrow fee accruals, dividend-on-short charges, corporate action timing and FX conversions on multi-currency accounts. Multi-PB funds also need a consolidated view of margin and financing across counterparties, which is usually built in the middle office.