Interest Rates and The Credit Crunch: New Formulas and Market Models

39 Pages Posted: 24 Jan 2009 Last revised: 11 May 2010

Date Written: February 5, 2009


We start by describing the major changes that occurred in the quotes of market rates after the 2007 subprime mortgage crisis. We comment on their lost analogies and consistencies, and hint on a possible, simple way to formally reconcile them. We then show how to price interest rate swaps under the new market practice of using different curves for generating future LIBOR rates and for discounting cash flows. Straightforward modifications of the market formulas for caps and swaptions will also be derived.

Finally, we will introduce a new LIBOR market model, which will be based on modeling the joint evolution of FRA rates and forward rates belonging to the discount curve. We will start by analyzing the basic lognormal case and then add stochastic volatility. The dynamics of FRA rates under different measures will be obtained and closed form formulas for caplets and swaptions derived in the lognormal and Heston (1993) cases.

Alternative, and more recent, formulations of multi-curve LIBOR market models can be downloaded at:

Keywords: credit crunch, credit, liquidity, market rates, forward curve, discount curve, bootstrapping, FRAs, swaps, caps, swaptions, LIBOR market models, measure changes, stochastic volatility, Heston volatility, closed form formulas

JEL Classification: E45, G13

Suggested Citation

Mercurio, Fabio, Interest Rates and The Credit Crunch: New Formulas and Market Models (February 5, 2009). Bloomberg Portfolio Research Paper No. 2010-01-FRONTIERS, Available at SSRN:

Fabio Mercurio (Contact Author)

Bloomberg L.P. ( email )

731 Lexington Avenue
New York, NY 10022
United States