<p>The returns <span class="math notranslate nohighlight">\(r_n\)</span> are modeled by a Student’s-t distribution whose scale (volatility) <span class="math notranslate nohighlight">\(R_n\)</span> is time varying and unknown. The prior for <span class="math notranslate nohighlight">\(\log R_n\)</span> is a Gaussian random walk, with an exponential distribution of the random walk step-size <span class="math notranslate nohighlight">\(\sigma\)</span>. An exponential prior is also taken for the Student’s-t degrees of freedom <span class="math notranslate nohighlight">\(\nu\)</span>. The generative process of the data is:</p>
0 commit comments