Index Administrator


WMBA currently collates,  administers and publishes the Repurchase Overnight Index Average ('RONIA') and Euro Overnight Index Average ('EURONIA') which were introduced in January 2007 and January 1999 respectively.

It embraces and fully supports the objectives of the IOSCO Principles for Financial Benchmarks ('IOSCO Principles') and the BMR to create a common framework for the regulation of indices used as benchmarks in financial markets. Whilst there is no requirement for all indices to be compliant with those regulations, WMBA shall where it is possible and proportionate to do so, apply, and monitor the framework to all indices that it administers,

As of 1st September 2022, WMBA & LEBA (Holdings) Limited, a group company, took over the administration of the RONIA and EURONIA indices  and will retain the same level of internal governance and oversight established during its administration by WMBA Limited.

It operates an oversight committee composed of external market experts in order to oversee and to challenges the index statements and methodology, together with the operational resilience and other matters related to the ongoing scrutiny  of publication “Dashboards.” In light of the widespread interest and importance of these indices, WMBA maintains its adherence to the service levels first developed as a critical benchmark in the UK, and further enhanced when SONIA was published under licence for the Bank of England. It regularly attends standing committees and convenes with stakeholders, their representatives, central banks and competent authorities to consider the well-functioning of the wholesale markets in general and the indices as a key tool within those.


A brief history of WMBA Limited; A market leader in governance of financial benchmarks

WMBA Limited was incorporated in 2008 to administer the data business of the European Venues & Intermediaries Association (previously known as the Wholesale Markets Brokers' Association).

A leader in the governance of financial indices, WMBA Limited was one of the first FCA approved Benchmark Administrators under the UK Benchmarks Regulation ('BMR') and formerly under the EU Benchmarks Regulation ('BMR') and its predecessor, FCA MAR from the outset of “Critical Benchmarks” in the spring of 2015. WMBA Limited was formerly listed on the Financial Conduct Authority (‘FCA’) 'Benchmarks Register' which lists entities that have been authorised or registered pursuant to Article 34 of the Benchmarks Regulation.

On the 1st of April 2015, SONIA, and RONIA, both of which were administered by WMBA Limited at the time, became specified benchmarks under the UK Financial Services and Markets Act 2000, and as such, WMBA Limited became regulated by the Financial Conduct Authority (FCA) for the activity of administering benchmarks.

WMBA Limited was previously the administrator of the Sterling Overnight Index Average ("SONIA"), introduced in March 1997, until the Bank of England took over the control of the Benchmark in April 2018. From that point, and until the methodology was changed in later 2019, WMBA Limited was the benchmark calculation agent and publisher for SONIA under a direct license from the Bank of England who became the Benchmark Administrator.

WMBA Limited ceased to be an Authorised Benchmark Administrator on 20th October 2022, at which point the RONIA and EURONIA benchmarks were recategorised to index status and thus no longer subject to the same intense scrutiny from the regulatory bodies. Details of WMBA Limited's FCA various authorisations and permissions across that period, along with regulatory waivers may be found on the FCA Financial Services Register under Financial Registration Number 679716.

WMBA, together with its sister association, LEBA have developed and administered indices across financial and non-financial instruments on behalf of its members and customers in order to aggregate venue activity and to promote fair and effective market structure.

From 20th October 2022, in light of the fact that the benchmarks were not used within the pricing of derivatives contracts under the meaning of BMR, UK supervision was deemed unnecessary and their status as “Regulated Data Benchmarks” realigned with the usage. The application was made to unwind the authorisation, and from that point, and with the approval of the UK authorities, the indices have been  published as solely as IOSCO compliant.


Head Office

WMBA & LEBA (Holdings) Limited
Warnford Court
29 Throgmorton Street

Telephone:  020 7947 4900
Facsimile:  020 3292 1592