Collateral Rehypothecation

Collateral rehypothecation is the practice of a firm that has received collateral from one counterparty using that same collateral again, to secure its own separate borrowing, trading, or financing needs, rather than simply holding it untouched until it is returned. A prime broker that holds securities pledged by a hedge fund client, for example, might pledge those same securities onward to raise its own short-term funding, as long as its agreement with the client permits it. Rehypothecation lets collateral circulate through the financial system multiple times rather than sitting idle, which is why it is closely tied to overall market liquidity.

The right to rehypothecate must be explicitly granted in the agreement between the original pledgor and the receiving firm; without it, the receiving firm is only permitted to hold the collateral, not use it. Rehypothecation is common in prime brokerage, repurchase agreements (repos), and securities lending, and it is one of the more heavily regulated aspects of collateral management because of the risk it creates for the original pledgor if the receiving firm fails.

Think of a tool-lending library where members pledge a deposit item, such as a spare set of tools, to borrow equipment. Now imagine the library itself takes those pledged tools and lends them out to other members, or uses them as its own security to borrow a van for deliveries. The original owner still expects to get their tools back eventually, but in the meantime, those same tools are being put to work somewhere else entirely, by someone the original owner never dealt with directly.

That is rehypothecation. The firm holding collateral is not just keeping it safe in a drawer; it is actively reusing it, often for purposes that have nothing to do with the original pledgor's trade. This makes the financial system more efficient, because the same pool of assets can support more than one transaction at a time, but it also means the original pledgor is now relying on a chain of parties, not just the one it dealt with directly, to eventually get its collateral back.

• It allows a firm such as a prime broker to fund its own operations more cheaply, using client collateral instead of raising fresh capital.
• It increases overall market liquidity, since the same assets can support several linked financing transactions rather than only one.
• It can lower the cost of financing passed back to the original client, since the receiving firm's ability to reuse collateral is often reflected in better financing terms.

If the firm that rehypothecated the collateral becomes insolvent, the original pledgor may find itself an unsecured creditor for the collateral it thought was simply being held on its behalf, rather than someone with a clear right to immediate return of a specific asset. This risk became widely visible during the 2008 financial crisis, when clients of a failed prime broker discovered that assets they believed were segregated had in fact been rehypothecated and were tied up in the firm's insolvency proceedings for years, a clear illustration of counterparty risk extending even to parties that thought they held safe, segregated collateral. The distinction between collateral that is merely held, similar to assets in a trust account, and collateral that has been rehypothecated is central to how quickly, and how fully, a pledgor can expect to recover its assets after a default.

Because of the risk it creates, rehypothecation is subject to specific disclosure and, in some jurisdictions, quantitative limits. In the United Kingdom and the European Union, rules following the crisis cap the amount of client collateral that can be rehypothecated and require clear, upfront disclosure of the practice, reflected in part in MiFID II. In the United States, similar protections for client assets were strengthened in the wake of the crisis and tied to broader reforms enacted through the Dodd-Frank Act. Firms must typically obtain explicit client consent before rehypothecating collateral and report the extent of rehypothecation to regulators.

Rehypothecation should not be confused with a party's own right to swap one posted asset for another of equal value; that practice changes which specific asset secures a given obligation but does not involve a third party reusing the collateral for an unrelated purpose. Rehypothecation specifically involves the receiving firm putting the collateral to work for its own separate ends, which is why it carries a materially different risk profile and a heavier regulatory disclosure burden.

• International Swaps and Derivatives Association (ISDA)
• Basel Committee on Banking Supervision