Service Navigation


Omnibus Segregated Account (OSA)

The omnibus segregation model allows Clearing Members (CMs) to segregate client positions and collateral (for multiple clients) from the Clearing Member's  proprietary positions and collateral.

Eurex Clearing's omnibus segregation models are highly flexible and aim to address the requirements of our members and their clients. The benefits for clients of omnibus segregation include:

  • porting
  • return of collateral (return segregated from the CM's proprietary business) and
  • compliance with EMIR requirements.


Within the omnibus segregation arrangements, position segregation for clients can be supported.

  • The Elementary Clearing Model (ECM) is an omnibus client segregation model. It provides for the segregation of proprietary positions and assets of a Clearing Member from its client-related positions and assets. 
  • Our omnibus offering provides Clearing Members with three options for the segregation of their clients’ positions and assets.

Position segregation:

  • The position account structure within the ECM supports the segregation of positions of Direct Disclosed Clients from the positions of their (indirect) clients. The accounts maintained in relation to indirect clients are offered as NOSA or GOSA and are linked to the relevant direct client. 

Asset segregation:


Elementary Clearing Model Value Based Allocation (ECM by value)

The assets pledged in the collateral account at the central securities depository (CSD) are held in the name of the Clearing Member without relation to a specific position account. However, at the CCP level, the margin collateral provided is allocated to cover the proprietary transactions and the client transactions although one collateral pool is set up.


Eurex Clearing intends to discontinue the offering of the Value Based Allocation method for the ECM as of 31 December 2019. Clearing Members who are requesting admission in 2019 or beyond this date are required to on-board under the Asset Based Allocation method.


Elementary Clearing Model Asset Based Allocation (ECM by asset)

The assets are provided by the Clearing Member to Eurex Clearing separately for own transactions of the Clearing Member and for client-related transactions of the Clearing Member. At least two collateral pools are required. On request of the Clearing Member, Eurex Clearing will establish additional pools to cover ECM Omnibus Transactions.

Elementary Clearing Model – CASS Transactions (ECM – CASS)

This setup is operationally and functionally the same as ECM by asset. Transactions designated as CASS Eligible Transactions are legally segregated from non-CASS Transactions and Eurex Clearing will sign trust acknowledgement letters in order to enable Clearing Members to comply with their obligations under the CASS rules of the United Kingdom Financial Conduct Authority (FCA). Dedicated account(s) at the CSD is required.


  • Direct Disclosed Client accounts qualify as GOSA. For DCs with System Access or Basic DCs only Eurex Transactions and OTC Interest Rate Derivatives Transactions are eligible for the clearing under OSA.
  • For each GOSA a separate position account shall be maintained. GOSA is available for the clearing of Eurex Transactions and OTC Derivatives Transactions reflecting the position of that specific Disclosed Direct Client or Indirect Client of such Disclosed Direct Client. Therefore, margin requirement is calculated on a gross basis for GOSA clients.
  • As each NOSA reflects positions of multiple clients the margin requirement calculation is performed on a net basis.
  • Collateral in an omnibus structure will always be shared across multiple clients and leads to fellow customer risk for any potential shortfall in a collateral pool in case of a Clearing Member default.
  • Collateral management options ensure the model is operationally simple to manage at the CCP.