Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-20T12:31:00.322Z Has data issue: false hasContentIssue false

Exponential utility indifference valuation in two Brownian settings with stochastic correlation

Published online by Cambridge University Press:  01 July 2016

Christoph Frei*
Affiliation:
ETH Zürich
Martin Schweizer*
Affiliation:
ETH Zürich
*
Postal address: Department of Mathematics, ETH Zürich, 8092 Zürich, Switzerland.
Postal address: Department of Mathematics, ETH Zürich, 8092 Zürich, Switzerland.
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We study the exponential utility indifference valuation of a contingent claim B in an incomplete market driven by two Brownian motions. The claim depends on a nontradable asset stochastically correlated with the traded asset available for hedging. We use martingale arguments to provide upper and lower bounds, in terms of bounds on the correlation, for the value VB of the exponential utility maximization problem with the claim B as random endowment. This yields an explicit formula for the indifference value b of B at any time, even with a fairly general stochastic correlation. Earlier results with constant correlation are recovered and extended. The reason why all this works is that, after a transformation to the minimal martingale measure, the value VB enjoys a monotonicity property in the correlation between tradable and nontradable assets.

Type
General Applied Probability
Copyright
Copyright © Applied Probability Trust 2008 

References

Becherer, D. (2006). Bounded solutions to backward SDEs with Jumps for utility optimization and indifference hedging. Ann. Appl. Prob. 16, 20272054.Google Scholar
Benth, F. E. and Karlsen, K. H. (2005). A PDE representation of the density of the minimal entropy martingale measure in stochastic volatility markets. Stochastics 77, 109137.Google Scholar
Delbaen, F. et al. (2002). Exponential hedging and entropic penalties. Math. Finance 12, 99123.CrossRefGoogle Scholar
Dubins, L., Feldman, J., Smorodinsky, M. and Tsirelson, B. (1996). Decreasing sequences of σ-fields and a measure change for Brownian motion. Ann. Prob. 24, 882904.Google Scholar
Föllmer, H. and Schweizer, M. (1991). Hedging of contingent claims under incomplete information. In Applied Stochastic Analysis (Stoch. Monogr. 5, eds Davis, M. and Elliott, R., Gordon and Breach, New York, pp. 389414.Google Scholar
Grasselli, M. R. and Hurd, T. R. (2007). Indifference pricing and hedging for volatility derivatives. Appl. Math. Finance 14, 303317.Google Scholar
Henderson, V. (2002). Valuation of claims on nontraded assets using utility maximization. Math. Finance 12, 351373.Google Scholar
Henderson, V. (2005). The impact of the market portfolio on the valuation, incentives and optimality of executive stock options. Quant. Finance 5, 3547.Google Scholar
Henderson, V. and Hobson, D. (2002). Real options with constant relative risk aversion. J. Econom. Dynam. Control 27, 329355.Google Scholar
Henderson, V. and Hobson, D. (2002). Substitute hedging. RISK 15, 7175.Google Scholar
Henderson, V. and Hobson, D. (2004). Utility indifference pricing—an overview. To appear in Indifference Pricing, ed. Carmona, R. Princeton University Press. Available at http://www.orfe.princeton.edu/∼vhenders.Google Scholar
Hu, Y., Imkeller, P. and Müller, M. (2005). Utility maximization in incomplete markets. Ann. Appl. Prob. 15, 16911712.CrossRefGoogle Scholar
Karatzas, I. and Shreve, S. (1998). Methods of Mathematical Finance. Springer, New York.Google Scholar
Kazamaki, N. (1994). Continuous Exponential Martingales and BMO (Lecture Notes in Math. 1579). Springer, New York.CrossRefGoogle Scholar
Mania, M. and Schweizer, M. (2005). Dynamic exponential utility indifference valuation. Ann. Appl. Prob. 15, 21132143.Google Scholar
Monoyios, M. (2006). Characterisation of optimal dual measures via distortion. Decis. Econom. Finance. 29, 95119.Google Scholar
Morlais, M.-A. (2007). Quadratic BSDEs driven by a continuous martingale and applications to the utility maximization problem. Available at http://arxiv.org/abs/math/0610749v2.Google Scholar
Musiela, M. and Zariphopoulou, T. (2004). An example of indifference prices under exponential preferences. Finance Stoch. 8, 229239.Google Scholar
Schachermayer, W. (2001). Optimal investment in incomplete markets when wealth may become negative. Ann. Appl. Prob. 11, 694734.CrossRefGoogle Scholar
Stoikov, S. and Zariphopoulou, T. (2004). Optimal investments in the presence of unhedgeable risks and under CARA preferences. To appear in IMA Vol. Series.Google Scholar
Tehranchi, M. (2004). Explicit solutions of some utility maximization problems in incomplete markets. Stochastic Process. Appl. 114, 109125.CrossRefGoogle Scholar
Zariphopoulou, T. (2001). A solution approach to valuation with unhedgeable risks. Finance Stoch. 5, 6182.CrossRefGoogle Scholar