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Estimating a Local (Time- and State-Dependent) Volatility Surface(A Linearization-Based Solution to the Ill-Posed Local Volatility Estimation Problem,and Non-Parametric Estimation of an Implied Volatility Surface with Martin Jermakyanfromhttp://www.gsb.georgetown.edu/dept/facserv/faculty/bodurthj/research/research.html) • Jim Bodurtha • Georgetown University • Chicago Risk Management ConferenceMay 7, 1998 - Chicago
Term Volatility Surfaces - • Shimko, Dumas, Fleming and Whaley ... • Ait-Sahalia-Lo, Longstaff, Elliot-Madan, Derman-Kani-Zhou… • Rubinstein, Rubinstein-Jackwerth ... Local Volatility Surfaces - • Avellanede • Bodurtha-Jermakyan • Dupire, Derman-Kani (interpolate artifical prices) • Lagnado-Oscher
Table 2: Example European FX Call Options, Pricing and Vol “Smile” Implied Vol across options (s0) = 20%
Binomial Tree Valuation Set upSee also Kamrad-Ritchken (1991)
Trinomial Lattice European Call Option Values and Volatilities
Figure 2: PHLX DM European Options Local Volatility Surface - 11/25/91(2/9/95-4/14/97 average bid-ask spread 0.64% and standard deviation 0.52%)
Other issues • Computation-estimation and benchmarking Restricted non-linear models vs. linearizations Higher-order regularizers (large GSVD problem) • Volatility surface dynamics • Exotics • American options • Interest rates • Convergence
5. A Finite Difference-Based Numerical Implementation - Change state variable (moving frame of coordinates), discretize in state and time, first-order forward difference for time derivatives, second-order central difference for state derivatives, and introduce artificial state boundary conditions for L,