Filtering for discretely observed jump diffusions Murray Pollock, Adam Johansen, Gareth Roberts Dept. Of Statistics, University Of Warwick murray.pollock@warwick.ac.uk www.warwick.ac.uk/mpollock September 20th, 2012 Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Problem Outline Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Framework I Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Framework II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Framework III Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Framework IV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Framework V Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? I Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? III Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? IV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? V Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? VI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? VII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? VIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? IX Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? X Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? XI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? XII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? XIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What is a Diffusion? XIV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick The Problem - Key Problem - Not possible to simulate entire diffusion sample paths. . . - . . . Finite representation. - . . . Transition density inaccessible. - What can we simulate? - ... Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick The Problem - Key Problem - Not possible to simulate entire diffusion sample paths. . . - . . . Finite representation. - . . . Transition density inaccessible. - What can we simulate? - ... Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick The Problem - Key Problem - Not possible to simulate entire diffusion sample paths. . . - . . . Finite representation. - . . . Transition density inaccessible. - What can we simulate? - ... Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick The Problem - Key Problem - Not possible to simulate entire diffusion sample paths. . . - . . . Finite representation. - . . . Transition density inaccessible. - What can we simulate? - ... Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick The Problem - Key Problem - Not possible to simulate entire diffusion sample paths. . . - . . . Finite representation. - . . . Transition density inaccessible. - What can we simulate? - ... Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? I Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? III Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? IV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? V Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? VI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? VII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? VIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? IX Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? X Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? XI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? XII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? XIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? XIV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? XV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? XVI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? XVII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? XVIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? XIX Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick What can we simulate? XX Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Discretisation - What about everything else? - “Discretize” diffusion dynamics. - Euler discretization, for instance (PJS09, Jav05). ( Xt +∆t = µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) + ν (Xt − ) w.p. e −λ(Xt − )∆t w.p. 1 − e −λ(Xt − )∆t - Miltstein, Shoji & Ozaki,. . . - Drawbacks? - Implicit error. Computationally expensive. Moving beyond ‘bootstrap’? Performance evaluated using (finely discretised) simulated data. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Discretisation - What about everything else? - “Discretize” diffusion dynamics. - Euler discretization, for instance (PJS09, Jav05). ( Xt +∆t = µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) + ν (Xt − ) w.p. e −λ(Xt − )∆t w.p. 1 − e −λ(Xt − )∆t - Miltstein, Shoji & Ozaki,. . . - Drawbacks? - Implicit error. Computationally expensive. Moving beyond ‘bootstrap’? Performance evaluated using (finely discretised) simulated data. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Discretisation - What about everything else? - “Discretize” diffusion dynamics. - Euler discretization, for instance (PJS09, Jav05). ( Xt +∆t = µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) + ν (Xt − ) w.p. e −λ(Xt − )∆t w.p. 1 − e −λ(Xt − )∆t - Miltstein, Shoji & Ozaki,. . . - Drawbacks? - Implicit error. Computationally expensive. Moving beyond ‘bootstrap’? Performance evaluated using (finely discretised) simulated data. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Discretisation - What about everything else? - “Discretize” diffusion dynamics. - Euler discretization, for instance (PJS09, Jav05). ( Xt +∆t = µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) + ν (Xt − ) w.p. e −λ(Xt − )∆t w.p. 1 − e −λ(Xt − )∆t - Miltstein, Shoji & Ozaki,. . . - Drawbacks? - Implicit error. Computationally expensive. Moving beyond ‘bootstrap’? Performance evaluated using (finely discretised) simulated data. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Discretisation - What about everything else? - “Discretize” diffusion dynamics. - Euler discretization, for instance (PJS09, Jav05). ( Xt +∆t = µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) + ν (Xt − ) w.p. e −λ(Xt − )∆t w.p. 1 − e −λ(Xt − )∆t - Miltstein, Shoji & Ozaki,. . . - Drawbacks? - Implicit error. Computationally expensive. Moving beyond ‘bootstrap’? Performance evaluated using (finely discretised) simulated data. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Discretisation - What about everything else? - “Discretize” diffusion dynamics. - Euler discretization, for instance (PJS09, Jav05). ( Xt +∆t = µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) + ν (Xt − ) w.p. e −λ(Xt − )∆t w.p. 1 − e −λ(Xt − )∆t - Miltstein, Shoji & Ozaki,. . . - Drawbacks? - Implicit error. Computationally expensive. Moving beyond ‘bootstrap’? Performance evaluated using (finely discretised) simulated data. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Discretisation - What about everything else? - “Discretize” diffusion dynamics. - Euler discretization, for instance (PJS09, Jav05). ( Xt +∆t = µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) + ν (Xt − ) w.p. e −λ(Xt − )∆t w.p. 1 − e −λ(Xt − )∆t - Miltstein, Shoji & Ozaki,. . . - Drawbacks? - Implicit error. Computationally expensive. Moving beyond ‘bootstrap’? Performance evaluated using (finely discretised) simulated data. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Discretisation - What about everything else? - “Discretize” diffusion dynamics. - Euler discretization, for instance (PJS09, Jav05). ( Xt +∆t = µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) + ν (Xt − ) w.p. e −λ(Xt − )∆t w.p. 1 − e −λ(Xt − )∆t - Miltstein, Shoji & Ozaki,. . . - Drawbacks? - Implicit error. Computationally expensive. Moving beyond ‘bootstrap’? Performance evaluated using (finely discretised) simulated data. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Discretisation - What about everything else? - “Discretize” diffusion dynamics. - Euler discretization, for instance (PJS09, Jav05). ( Xt +∆t = µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) µ (Xt ) ∆t + σ (Xt ) N(0, ∆t ) + ν (Xt − ) w.p. e −λ(Xt − )∆t w.p. 1 − e −λ(Xt − )∆t - Miltstein, Shoji & Ozaki,. . . - Drawbacks? - Implicit error. Computationally expensive. Moving beyond ‘bootstrap’? Performance evaluated using (finely discretised) simulated data. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Talk Outline - Problem Outline & Motivation. - Area Estimator - Exact Algorithm (BPRF06, BPR08, PJR12a) - Jump Exact Algorithm (CR10, Gon11) - Filtering for Jump Diffusions (FPR08, FPRS10, PJR12b) - Other (Related) Work. (PJR12a, PJR12b) - Questions (& Hopefully) Answers. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Talk Outline - Problem Outline & Motivation. - Area Estimator - Exact Algorithm (BPRF06, BPR08, PJR12a) - Jump Exact Algorithm (CR10, Gon11) - Filtering for Jump Diffusions (FPR08, FPRS10, PJR12b) - Other (Related) Work. (PJR12a, PJR12b) - Questions (& Hopefully) Answers. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Talk Outline - Problem Outline & Motivation. - Area Estimator - Exact Algorithm (BPRF06, BPR08, PJR12a) - Jump Exact Algorithm (CR10, Gon11) - Filtering for Jump Diffusions (FPR08, FPRS10, PJR12b) - Other (Related) Work. (PJR12a, PJR12b) - Questions (& Hopefully) Answers. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Talk Outline - Problem Outline & Motivation. - Area Estimator - Exact Algorithm (BPRF06, BPR08, PJR12a) - Jump Exact Algorithm (CR10, Gon11) - Filtering for Jump Diffusions (FPR08, FPRS10, PJR12b) - Other (Related) Work. (PJR12a, PJR12b) - Questions (& Hopefully) Answers. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Talk Outline - Problem Outline & Motivation. - Area Estimator - Exact Algorithm (BPRF06, BPR08, PJR12a) - Jump Exact Algorithm (CR10, Gon11) - Filtering for Jump Diffusions (FPR08, FPRS10, PJR12b) - Other (Related) Work. (PJR12a, PJR12b) - Questions (& Hopefully) Answers. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Talk Outline - Problem Outline & Motivation. - Area Estimator - Exact Algorithm (BPRF06, BPR08, PJR12a) - Jump Exact Algorithm (CR10, Gon11) - Filtering for Jump Diffusions (FPR08, FPRS10, PJR12b) - Other (Related) Work. (PJR12a, PJR12b) - Questions (& Hopefully) Answers. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Talk Outline - Problem Outline & Motivation. - Area Estimator - Exact Algorithm (BPRF06, BPR08, PJR12a) - Jump Exact Algorithm (CR10, Gon11) - Filtering for Jump Diffusions (FPR08, FPRS10, PJR12b) - Other (Related) Work. (PJR12a, PJR12b) - Questions (& Hopefully) Answers. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Area Estimator Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Expectations of Positive RVs Goal. . . Evaluate E(P ) for some r.v. P ∈ R+ Suppose for now. . . P ∈ [0, 1] u ∼ U [0, 1] Consider a biased coin Cp . . . Heads (1) if u ≤ P Tails (0) if u > P Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Expectations of Positive RVs Goal. . . Evaluate E(P ) for some r.v. P ∈ R+ Suppose for now. . . P ∈ [0, 1] u ∼ U [0, 1] Consider a biased coin Cp . . . Heads (1) if u ≤ P Tails (0) if u > P Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Expectations of Positive RVs Goal. . . Evaluate E(P ) for some r.v. P ∈ R+ Suppose for now. . . P ∈ [0, 1] u ∼ U [0, 1] Consider a biased coin Cp . . . Heads (1) if u ≤ P Tails (0) if u > P Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Expectations of Positive RVs Why is this interesting. . . ? P Cp = 1 = E 1 u ≤ P ! = E E 1 u ≤ P P ! = E P Cp = 1P =EP - P(X ) = E(1X ) - Tower Property - P(X ) = E(1X ) To estimate E P unbiasedly we can simply throw a Cp coin Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator Let’s consider an example. . . Suppose we want to evaluate, E ( Z P := E exp − T n If 0 ≤ f (t ) ≤ M then P := exp − (P ) = P ⇒ find and flip Cp E RT 0 0 ) f (t ) dt o f (t ) dt ∈ [0, 1] Consider a Poisson process with instantaneous rate f (t ) on [0, T ], ( Z P N = 0 = exp − T ) f (t ) dt 0 PN =0 ≡P=EP Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator Let’s consider an example. . . Suppose we want to evaluate, E ( Z P := E exp − T n If 0 ≤ f (t ) ≤ M then P := exp − (P ) = P ⇒ find and flip Cp E RT 0 0 ) f (t ) dt o f (t ) dt ∈ [0, 1] Consider a Poisson process with instantaneous rate f (t ) on [0, T ], ( Z P N = 0 = exp − T ) f (t ) dt 0 PN =0 ≡P=EP Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator Let’s consider an example. . . Suppose we want to evaluate, E ( Z P := E exp − T n If 0 ≤ f (t ) ≤ M then P := exp − (P ) = P ⇒ find and flip Cp E RT 0 0 ) f (t ) dt o f (t ) dt ∈ [0, 1] Consider a Poisson process with instantaneous rate f (t ) on [0, T ], ( Z P N = 0 = exp − T ) f (t ) dt 0 PN =0 ≡P=EP Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator Let’s consider an example. . . Suppose we want to evaluate, E ( Z P := E exp − T n If 0 ≤ f (t ) ≤ M then P := exp − (P ) = P ⇒ find and flip Cp E RT 0 0 ) f (t ) dt o f (t ) dt ∈ [0, 1] Consider a Poisson process with instantaneous rate f (t ) on [0, T ], ( Z P N = 0 = exp − T ) f (t ) dt 0 PN =0 ≡P=EP Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator Let’s consider an example. . . Suppose we want to evaluate, E ( Z P := E exp − T n If 0 ≤ f (t ) ≤ M then P := exp − (P ) = P ⇒ find and flip Cp E RT 0 0 ) f (t ) dt o f (t ) dt ∈ [0, 1] Consider a Poisson process with instantaneous rate f (t ) on [0, T ], ( Z P N = 0 = exp − T ) f (t ) dt 0 PN =0 ≡P=EP Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator Let’s consider an example. . . Suppose we want to evaluate, E ( Z P := E exp − T n If 0 ≤ f (t ) ≤ M then P := exp − (P ) = P ⇒ find and flip Cp E RT 0 0 ) f (t ) dt o f (t ) dt ∈ [0, 1] Consider a Poisson process with instantaneous rate f (t ) on [0, T ], ( Z P N = 0 = exp − T ) f (t ) dt 0 PN =0 ≡P=EP Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator I The algorithm. . . Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator III Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator IV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator V Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator VI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator VII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator VIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator IX Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator X Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XIV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XVI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XVII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XVIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XIX Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XX Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XXI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Retrospective Area Estimator XXII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Denisty - First consider no jumps - Transform Diffusion - Lamperti Transform dXt = α(Xt ) dt + dBt - Propose sample paths (which can be simulated) - Brownian motion. - Absolutely continuous. - Accept or reject. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Denisty - First consider no jumps - Transform Diffusion - Lamperti Transform dXt = α(Xt ) dt + dBt - Propose sample paths (which can be simulated) - Brownian motion. - Absolutely continuous. - Accept or reject. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Denisty - First consider no jumps - Transform Diffusion - Lamperti Transform dXt = α(Xt ) dt + dBt - Propose sample paths (which can be simulated) - Brownian motion. - Absolutely continuous. - Accept or reject. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Denisty - First consider no jumps - Transform Diffusion - Lamperti Transform dXt = α(Xt ) dt + dBt - Propose sample paths (which can be simulated) - Brownian motion. - Absolutely continuous. - Accept or reject. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Denisty - First consider no jumps - Transform Diffusion - Lamperti Transform dXt = α(Xt ) dt + dBt - Propose sample paths (which can be simulated) - Brownian motion. - Absolutely continuous. - Accept or reject. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density I Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density III Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density IV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density V Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density VI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density VII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density VIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density IX Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density X Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density XI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density XII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density XIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density XIV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density XV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density XVI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Transition Density XVII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm Exact Algorithm 1 Simulate end point - y ∼ h 2 Propose sample bridge 3 Accept or Reject proposed sample bridge (and GOTO 1) Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm I Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm III Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm IV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm V Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm VI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm VII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm VIII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm IX Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm X Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Exact Algorithm XI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Random Weights I Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Random Weights II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Random Weights III Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Poisson Estimator I Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Poisson Estimator - Key Idea: Poisson Estimator - Simulate unbiased importance weight, EWsx,,ty " t ( Z exp − )# φ(Xu ) du s - What if φ(Xu ) ∈ [0, M ]? - Broader class of Poisson Estimators - Unbiased - Finite Variance (Generalised Poisson Estimators (FPR08)) - Positivity (Wald Generalised Poisson Estimator (FPRS10)) - Auxiliary Poisson Estimators (APES (PJR12b)) - Generalised APES (GRAPES (PJR12b) - Jump Diffusions) Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Poisson Estimator - Key Idea: Poisson Estimator - Simulate unbiased importance weight, EWsx,,ty " t ( Z exp − )# φ(Xu ) du s - What if φ(Xu ) ∈ [0, M ]? - Broader class of Poisson Estimators - Unbiased - Finite Variance (Generalised Poisson Estimators (FPR08)) - Positivity (Wald Generalised Poisson Estimator (FPRS10)) - Auxiliary Poisson Estimators (APES (PJR12b)) - Generalised APES (GRAPES (PJR12b) - Jump Diffusions) Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Poisson Estimator - Key Idea: Poisson Estimator - Simulate unbiased importance weight, EWsx,,ty " t ( Z exp − )# φ(Xu ) du s - What if φ(Xu ) ∈ [0, M ]? - Broader class of Poisson Estimators - Unbiased - Finite Variance (Generalised Poisson Estimators (FPR08)) - Positivity (Wald Generalised Poisson Estimator (FPRS10)) - Auxiliary Poisson Estimators (APES (PJR12b)) - Generalised APES (GRAPES (PJR12b) - Jump Diffusions) Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Poisson Estimator - Key Idea: Poisson Estimator - Simulate unbiased importance weight, EWsx,,ty " t ( Z exp − )# φ(Xu ) du s - What if φ(Xu ) ∈ [0, M ]? - Broader class of Poisson Estimators - Unbiased - Finite Variance (Generalised Poisson Estimators (FPR08)) - Positivity (Wald Generalised Poisson Estimator (FPRS10)) - Auxiliary Poisson Estimators (APES (PJR12b)) - Generalised APES (GRAPES (PJR12b) - Jump Diffusions) Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Poisson Estimator - Key Idea: Poisson Estimator - Simulate unbiased importance weight, EWsx,,ty " t ( Z exp − )# φ(Xu ) du s - What if φ(Xu ) ∈ [0, M ]? - Broader class of Poisson Estimators - Unbiased - Finite Variance (Generalised Poisson Estimators (FPR08)) - Positivity (Wald Generalised Poisson Estimator (FPRS10)) - Auxiliary Poisson Estimators (APES (PJR12b)) - Generalised APES (GRAPES (PJR12b) - Jump Diffusions) Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Particle Filter I Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Particle Filter II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Particle Filter III Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Particle Filter IV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Jump Transition Density Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Jump Transition Density I Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Jump Transition Density II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Jump Exact Algorithm I Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Jump Exact Algorithm II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Jump Exact Algorithm III Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Jump Exact Algorithm IV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Jump Exact Algorithm V Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Jump Exact Algorithm VI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Jump Exact Algorithm VII Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Example Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Example: Particle Filtering for Jump Diffusions I An Example. . . Exact Particle Filtering for Jump Diffusions In Practice! Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Example: Particle Filtering for Jump Diffusions II Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Example: Particle Filtering for Jump Diffusions III Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Example: Particle Filtering for Jump Diffusions IV Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Example: Particle Filtering for Jump Diffusions V Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Example: Particle Filtering for Jump Diffusions VI Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Other (Related) Work Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Other (Related) Work Current Work - Poisson Estimator - As discussed. . . - minu∈[s ,t ] α2 (Xu ) + α0 (Xu ) - Exact Algorithm - Alternative to EA3 (EA4 - ‘Mondrian’ EA) - EA3 Implementation - Jump EA - -Strong Simulation (BPR12) - Initialisation - Various Sampling Steps - Extensions Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Other (Related) Work Current Work - Poisson Estimator - As discussed. . . - minu∈[s ,t ] α2 (Xu ) + α0 (Xu ) - Exact Algorithm - Alternative to EA3 (EA4 - ‘Mondrian’ EA) - EA3 Implementation - Jump EA - -Strong Simulation (BPR12) - Initialisation - Various Sampling Steps - Extensions Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick Other (Related) Work Current Work - Poisson Estimator - As discussed. . . - minu∈[s ,t ] α2 (Xu ) + α0 (Xu ) - Exact Algorithm - Alternative to EA3 (EA4 - ‘Mondrian’ EA) - EA3 Implementation - Jump EA - -Strong Simulation (BPR12) - Initialisation - Various Sampling Steps - Extensions Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick References I [BPR08] A. Beskos, O. Papaspiliopoulos, and G. O. Roberts. A factorisation of diffusion measure and finite sample path constructions. Methodology and Computing in Applied Probability, 10:85–104, 2008. [BPR12] A. Beskos, S. Peluchetti, and G. O. Roberts. -strong simulation of the brownian path. Bernoulli., 2012. [BPRF06] A. Beskos, O. Papaspiliopoulos, G.O. Roberts, and P. Fearnhead. Exact and computationally effcient likelihood-based estimation for discretely observed diffusion processes (with discussion). Journal of the Royal Statistical Society, Series B (Statistical Methodology)., 68(3):333–382, 2006. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick References II [CR10] B. Casella and G. O. Roberts. Exact simulation of jump-diffusion processes with monte carlo applications. Methodology and Computing in Applied Probability, 13(3):449–473, 2010. [FPR08] P. Fearnhead, O. Papaspiliopoulos, and G. O. Roberts. Particle filters for partially-observed diffusions. Journal of the Royal Statistical Society, Series B (Statistical Methodology)., 70(4):755–777, 2008. [FPRS10] P. Fearnhead, O. Papaspiliopoulos, G. Roberts, and A. Stuart. Random-weight particle filtering of continuous time processes. Journal of the Royal Statistical Society, Series B (Statistical Methodology)., 72(4):497–512, 2010. [Gon11] F. Gonçalves. Exact simulation and Monte Carlo inference for jump-diffusion processes. PhD thesis, Dept. Of Statistics, University of Warwick., 2011. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick References III [Jav05] A. Javaheri. Inside Volatility Arbitrage. Wiley., 1st edition, 2005. [PJR12a] M. Pollock, A. M. Johansen, and G. O. Roberts. EA4. Technical report, CRISM, Department of Statistics, University of Warwick., 2012. [PJR12b] M. Pollock, A. M. Johansen, and G. O. Roberts. Exact Particle Filters. Technical report, CRISM, Department of Statistics, University of Warwick., 2012. [PJS09] N. Polson, M. Johannes, and J. Stroud. Optimal filtering of jump-diffusions: Extracting latent states from asset prices. Review of Financial Studies, 22(7):2259–2299, 2009. Murray Pollock (University Of Warwick) Filtering for jump diffusions SMC 2012 – Warwick