For a long time interest-rate models were built on a single yield curve used both for discounting and forwarding. However, the crisis that has affected financial markets in the last years led market players to revise this assumption and accommodate basis-swap spreads, whose remarkable widening...

Recent empirical studies on interest rate derivatives have shown that the volatil- ity structure of interest rates is frequently humped. Mercurio and Moraleda (1996) and Moraleda and Vorst (1996a) have modelled interest rate dynamics in such a way that humped volatility structures are possible...