Daily Spread Curves and Ester

Abstract

In this short note, we describe a simple yet accurate way to set up a rate curve defined by daily forward rates that are computed as a spread over the daily forward rates of a reference rate curve. One current use case of interest is to build an Ester curve from an Eonia curve using the (constant) Ester-Eonia spread defined by the ECB (-8.5 bp). We derive error bounds and test the method with real market data in ORE resp. QuantLib.