Risk magazine/Technical paper
A dynamic model for hard-to-borrow stocks
Traders with short positions in stocks that are subject to short-selling restrictions risk being 'bought in', in the sense that their positions may be closed out by the clearing firm at market prices. Marco Avellaneda and Mike Lipkin present a model for…
Pricing options on film revenue
This article illustrates two models for cumulative revenues from films, a time-changed gamma process and a compound Poisson process, and how these models can be used to price options. Don Chance, Eric Hillebrand and Jimmy Hilliard find that while both…
Managing diversification
Attilio Meucci introduces a diversification index that represents the effective number of bets in a portfolio. With this index, based on entropy and constrained principal component analysis, he performs mean-diversification management adjusted for…
Scaling conditional tail probability and quantile estimators
John Cotter presents a novel procedure for scaling relatively high-frequency tail probability and quantile estimates for the conditional distribution of returns
Factor models for credit correlation
Stewart Inglis, Alex Lipton and Artur Sepp present an extension of the static factor model for pricing credit correlation products introduced by Lipton (2006) and detailed in Inglis & Lipton (2007)
Accelerated ensemble Monte Carlo simulation
Traditional vanilla methods of Monte Carlo simulation can be extremely time-consuming if accurate estimation of the loss distribution is required. Kevin Thompson and Alistair McLeod show that the ensemble Monte Carlo method, introduced here,…
Smile dynamics III
In two articles published in 2004 and 2005 in Risk, Lorenzo Bergomi assessed the structural limitations of existing models for equity derivatives and introduced a new model based on the direct modelling of the joint dynamics of the spot and the implied…
Error of VAR by overlapping intervals
When overlapping intervals in time series are used, volatility and price changes' percentiles are underestimated. Consequently, value-at-risk is also underestimated. Heng Sun, Izzy Nelken, Guowen Han and Jiping Guo measure the size of this underestimation
Joining the SABR and Libor models together
Fabio Mercurio and Massimo Morini propose a Libor market model consistent with SABR dynamics and develop approximations that allow for the use of the SABR formula with modified inputs. They verify that the approximations are acceptably precise, imply…
Robust asset allocation under model risk
Financial investors often develop a multitude of models to explain financial securities' dynamics, none of which they can fully trust. Model risk (also referred to as ambiguity) prevents investors from using the classical framework of expected utility…
Being two-faced over counterparty credit risk
A recent trend in quantifying counterparty credit risk for over-the-counter derivatives has involved taking into account the bilateral nature of the risk so that an institution would consider their counterparty risk to be reduced in line with their own…
Zur Validierung von Marktrisikomodellen
Der Neueste Stand - Marktrisiko
Rates squared
Vladimir Piterbarg introduces a conveniently parameterised class of multi-factor quadratic Gaussian models, develops calibration formulas, and explains the advantages of this class of models over alternatives currently available for pricing and risk…
Seasonally adjusted prices for inflation-linked bonds
Inflation-linked bond markets are used ever more frequently by policy-makers, economists and commentators to assess the market's opinion about the future path of inflation and real yields. But important effects such as seasonality and carry are often…
Opinioni assolutamente flessibili: tra teoria e pratica
Approfondimenti Investment Management
Juggling snowballs
Previous work on the valuation of cancellable snowball swaps in the Libor market model suggested the use of nested Monte Carlo simulations was needed to obtain accurate prices. Here, Christopher Beveridge and Mark Joshi introduce new techniques that…
Delta and vega hedging in the SABR and LMM-SABR models
Riccardo Rebonato, Andrey Pogudin and Richard White examine the hedging performance of the SABR and LMM-SABR models using real market data. As a by-product, they gain indirect evidence about how well specified the two models are. The results are…
Credit remains the focus
Degree of Influence
Component VAR for a non-normal world
Market Risk
Struck off
Credit default swaps (CDSs) offer protection against issuer default, and in general the protection is paid via a running spread rather than upfront. When the par spread changes, the contract cannot be unwound without leaving a default-contingent annuity…
Parameter estimation with k-means clustering
Ever since the pioneering work of Cox, Ross & Rubinstein (1979), tree models have been popular as an asset pricing method. However, statistical estimation of the parameters of tree models has been less studied. In this article, Kiseop Lee and Mingxin Xu…
Un modello di Vasicek multistato con correlazione tra tassi di default e perdita
Approfondimenti - Rischio di credito
Smile dynamics III
In two articles published in 2004 and 2005 in Risk, Lorenzo Bergomi assessed the structural limitations of existing models for equity derivatives and introduced a new model based on the direct modelling of the joint dynamics of the spot and the implied…
Fully flexible views: theory and practice
Attilio Meucci proposes a unified methodology to input non-linear views from any number of users in fully general non-normal markets and perform, among others, stress testing, scenario analysis and ranking allocation. He walks the reader through the…