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Custodian and Prime Broker Default Risk for Client Assets

Article Quant Q&A · Author: SRKX

Summary

The document explains why ownership records alone may not determine what happens to a client’s securities or cash if a custodian or prime broker fails. The outcome depends on account arrangements, legal contracts, and whether assets were kept separate, pooled, or reused by the intermediary. It contrasts cash balances, which may be treated as general claims in insolvency, with securities that may be held separately.

A key risk is rehypothecation: a prime broker may use client securities to finance credit or leverage. If the broker defaults, affected assets may be exposed to losses, though netting against client liabilities can matter. Suggested mitigations include negotiating limits on reuse, reducing indebtedness, holding securities rather than cash when reuse is unavailable, and using cash protection or diversification arrangements. The answer is explicitly general rather than legal advice; jurisdiction, contract language, and insolvency treatment can change the result, so it does not promise recovery in any particular case.

Key ideas

  • Cash held at a prime broker may be pooled and treated as a claim against the broker in insolvency.
  • Securities may also be exposed if the broker can rehypothecate them under the client agreement.
  • Netting provisions and the client’s liabilities can affect the recovery of reused assets.
  • Negotiated reuse limits, lower indebtedness, and cash protection arrangements can reduce some counterparty exposure.
  • The outcome depends on contracts and applicable legal treatment, so the discussion is not a case-specific legal conclusion.

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Full text
# What happens if a custodian bank defaults?


# What happens if a custodian bank defaults?












This question follows up my answer and the related comment to this post and in general relates to counterparty risk.

When you buy a financial asset, this asset goes in your account at your custodian bank.

So assume you bought some Swiss Government bond and that your custodian is, say, JP Morgan. What happens if JP Morgan goes bankrupt like Lehman Brothers?

Are you sure to keep your bond? Are you sure to lose it?

The underlying question is: to the Swiss government, who is the bond holder? You, or the bank?

## Answer by assylias (score 8, accepted)

https://quant.stackexchange.com/a/4209

The short answer is that it depends ;-) The long answer is complicated because it is a complicated topic. Disclaimers:

- I am not a lawyer (feel free to comment if I have overlooked anything)

- I believe the information below to be fairly standard, but

- counterparty risk is eventually driven by contracts and has to be envisaged on a case by case basis

Cash is a counterparty risk

Imagine that you are a fund and your assets are held at a prime broker (PB). Your cash balances will typically be comingled with other clients' cash balances on the PB balance sheet. In case of a bankrupcy, this cash will form part of the liquidation process and you will rank as one of the PB's general creditors (= you will probably not recoup all of your cash, if at all - and even if you do, it will take time).

One way to mitigate that risk is to invest the cash in securities, which are not comingled with the bank's assets. Unless...

Some of your other assets might be at risk too: rehypothecation

A typical prime brokerage agreement would also include a rehypothecation clause under which the PB has the right to use your assets, in other words to transfer some of your assets from your account to their account.

The main purpose of rehypothecation is to enable the PB to finance the cost of providing your fund with leverage: the PB will typically use those securities as collateral to raise some cash which they can then lend to you, which in turn enables you to leverage your portfolio.

In your case, if the Swiss bonds you just bought are part of the assets that have been used by your PB, and your PB goes bankrupt, those bonds will represent a potential loss - unless you can net them with liabilities that you owe to your PB (i.e. assuming there is a master netting agreement, which there generally is).

The amount that the PB can rehypothecate is generally a function of how much indebtedness you have with them. The PB will then use some of your assets, for an amount up to x% of that indebtedness. How the indebtedness is calculated and how x is determined depends on various factors (x = 140% seems to be standard).

How to mitigate the risk?

There are various ways to mitigate the counterparty risk, such as:

- Negotiation! Getting better terms on the rehypothecation side helps. If counterparty risk in an absolute concern, you can even negotiate to completely remove the possibility that your PB use your assets. But they will charge you more to offset that financing loss

- Reducing your indebtedness (think resetting OTC derivatives transactions for example)

- If you are in a situation where your PB can't rehypothecate your assets because you don't have any indebtedness, buying government bonds instead of holding cash will reduce your risk - that is the typical situation where buying securities with negative yields can make sense

- Using cash protection schemes, such as the FSA Client Money Rules, which enable you to diversify the banks at which your cash is held

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.