On 21 September 2017 the European Central Bank (ECB) announced that it would develop a euro unsecured overnight interest rate based on data already available to the Eurosystem. The interest rate, which would be produced before 2020, would complement existing benchmark rates produced by the private sector and serve as a backstop reference rate. This interest rate would be based entirely on transactions in euro that are reported by banks in the ECB’s money market statistical reporting (MMSR).