EONIA was the euro money market’s benchmark for unsecured overnight interest rates. Until 30 September 2019, it was derived from euro interbank lending rates submitted by a panel of participating banks and averaged according to transaction volumes. A revised calculation applied from 2 October 2019: the rate was set at the euro short-term rate (€STR) with an adjustment of 8.5 basis points. The €STR used in this calculation was based on money-market activity recorded on the previous TARGET2 business day. EONIA ceased to be published on 3 January 2022; the €STR subsequently became the market’s relevant overnight reference rate.
Source: European Central Bank (ECB) (source). This glossary entry is an independently worded adaptation of the cited information.