{"id":4554,"date":"2022-11-03T13:24:57","date_gmt":"2022-11-03T05:24:57","guid":{"rendered":"https:\/\/fanyuzhao.com\/?p=4554"},"modified":"2022-11-03T17:09:00","modified_gmt":"2022-11-03T09:09:00","slug":"brownian-motion-to-normal-distribution","status":"publish","type":"post","link":"https:\/\/fanyuzhao.com\/?p=4554","title":{"rendered":"Brownian Motion to Normal Distribution"},"content":{"rendered":"\n<p>Codes are shown in the HTML file.<\/p>\n\n\n\n<div class=\"wp-block-file\"><a id=\"wp-block-file--media-a0162314-c31b-4557-b47b-795e2f5e1f9b\" href=\"https:\/\/fanyuzhao.com\/wp-content\/uploads\/2022\/11\/Brownian-Motion-Normal-Dist-1.html\">Brownian-Motion-Normal-Dist<\/a><a href=\"https:\/\/fanyuzhao.com\/wp-content\/uploads\/2022\/11\/Brownian-Motion-Normal-Dist-1.html\" class=\"wp-block-file__button\" download aria-describedby=\"wp-block-file--media-a0162314-c31b-4557-b47b-795e2f5e1f9b\">Download<\/a><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">Markov Property<\/h4>\n\n\n\n<p>The Markov Property states that the expected value of the random variable \\(S_i\\) conditional upon all of the past events only depends on the previous value \\(S_{i\u22121}\\). The implication of the Markov Property is that the <\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Martingale Property<\/h4>\n\n\n\n<p>best expectation of future price, \\((S_{t+k}\\), is the current price, \\(S_t\\). The current price contains all the information until now.<\/p>\n\n\n\n<p>$$ \\mathbb{E}(S_{t+k}|F_t)=S_t, \\text{  for k&gt;=0} $$<\/p>\n\n\n\n<p>That is called the Martingale Property.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Quadratic Variation<\/h4>\n\n\n\n<p>The Quadratic Variation is defined as,<\/p>\n\n\n\n<p>$$ \\sum_{i=1}^k (S_i &#8211; S_{i-1})^2 $$<\/p>\n\n\n\n<p>In the coin toss case, each movement must be either &#8220;1&#8221; or &#8220;-1&#8221;, so \\(S_i &#8211; S_{i-1} = \\pm 1\\). Thus, \\((S_i &#8211; S_{i-1})^2 =1\\) for all &#8220;i&#8221;. Therefore, the Quadratic Variation equals &#8220;k&#8221;.<\/p>\n\n\n\n<div class=\"wp-block-file\"><a id=\"wp-block-file--media-31041382-3e47-454f-9806-1a5d2d4d6394\" href=\"https:\/\/fanyuzhao.com\/wp-content\/uploads\/2022\/11\/Brownian-Motion-sub-insights-1.html\">Brownian-Motion-sub-insights-1<\/a><a href=\"https:\/\/fanyuzhao.com\/wp-content\/uploads\/2022\/11\/Brownian-Motion-sub-insights-1.html\" class=\"wp-block-file__button\" download aria-describedby=\"wp-block-file--media-31041382-3e47-454f-9806-1a5d2d4d6394\">Download<\/a><\/div>\n\n\n\n<p><\/p>\n\n\n\n<h4 class=\"wp-block-heading\">A Realisation<\/h4>\n\n\n\n<p>Here below is the Code Realisation of a Brownian motion &#8211; Chapter 5.6 Paul Wilmott Introduces Quantitative Finance.<\/p>\n\n\n\n<div class=\"wp-block-file\"><a id=\"wp-block-file--media-34b5b6ba-4315-4920-8b27-17dd394e7815\" href=\"https:\/\/fanyuzhao.com\/wp-content\/uploads\/2022\/11\/Codes-for-Chapter-5.6-Brownian-motion-Paul-Wilmott-Introduces-Quantitative-Finance-1.html\">Codes-for-Chapter-5.6-Brownian-motion-Paul-Wilmott-Introduces-Quantitative-Finance-1<\/a><a href=\"https:\/\/fanyuzhao.com\/wp-content\/uploads\/2022\/11\/Codes-for-Chapter-5.6-Brownian-motion-Paul-Wilmott-Introduces-Quantitative-Finance-1.html\" class=\"wp-block-file__button\" download aria-describedby=\"wp-block-file--media-34b5b6ba-4315-4920-8b27-17dd394e7815\">Download<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Codes are shown in the HTML file. Markov Property The Markov Property states that the expected value of the random variable \\(S_i\\) conditional upon all of the past events only depends on the previous value \\(S_{i\u22121}\\). The implication of the Markov Property is that the Martingale Property best expectation of future price, \\((S_{t+k}\\), is the &hellip; <a href=\"https:\/\/fanyuzhao.com\/?p=4554\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Brownian Motion to Normal Distribution<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,18,26],"tags":[],"_links":{"self":[{"href":"https:\/\/fanyuzhao.com\/index.php?rest_route=\/wp\/v2\/posts\/4554"}],"collection":[{"href":"https:\/\/fanyuzhao.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fanyuzhao.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fanyuzhao.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fanyuzhao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4554"}],"version-history":[{"count":31,"href":"https:\/\/fanyuzhao.com\/index.php?rest_route=\/wp\/v2\/posts\/4554\/revisions"}],"predecessor-version":[{"id":4596,"href":"https:\/\/fanyuzhao.com\/index.php?rest_route=\/wp\/v2\/posts\/4554\/revisions\/4596"}],"wp:attachment":[{"href":"https:\/\/fanyuzhao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4554"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fanyuzhao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4554"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fanyuzhao.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4554"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}