{"id":860,"date":"2026-09-22T12:41:44","date_gmt":"2026-09-22T12:41:44","guid":{"rendered":"https:\/\/www.henrylahr.com\/?p=860"},"modified":"2026-09-22T12:44:34","modified_gmt":"2026-09-22T12:44:34","slug":"non-gaussian-stock-price-synchronicity","status":"publish","type":"post","link":"https:\/\/www.henrylahr.com\/?p=860","title":{"rendered":"Non-Gaussian stock price synchronicity"},"content":{"rendered":"<p>The full paper is available at <a href=\"https:\/\/ssrn.com\/abstract=7364922\">SSRN<\/a> (this version: 22 September 2026).<\/p>\n<p>Traditional stock price synchronicity measures are based on the coefficient of determination (R-squared) from a linear market model and therefore capture only dependence explained by linear correlation. We develop a measure of non-Gaussian stock price synchronicity based on mutual information. It is defined as the difference between observed mutual information and the mutual information implied by a Gaussian dependence structure with the same correlation coefficient, and is related to the Kullback-Leibler divergence between the observed and Gaussian copulas. Using a sample of US firms, we show that stock-market dependence frequently exceeds that implied by linear correlation alone and exhibits substantial cross-sectional and time-series variation. Non-Gaussian synchronicity is positively associated with R&amp;D activity and market-to-book ratios and negatively associated with asset tangibility, while traditional measures of downside vulnerability have little explanatory power. Conventional R-squared-based and rank-based synchronicity measures exhibit remarkably similar determinants, suggesting that they capture a common dependence-strength dimension, whereas non-Gaussian synchronicity is explained by a distinct set of firm characteristics. The evidence suggests that non-Gaussian synchronicity captures economically meaningful features of the dependence structure beyond its overall strength and that it primarily reflects common upside optionality rather than common downside vulnerability.<\/p>\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2011-scaled.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"365\" src=\"https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2011-1024x365.png\" alt=\"\" class=\"wp-image-861\" srcset=\"https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2011-1024x365.png 1024w, https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2011-300x107.png 300w, https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2011-768x274.png 768w, https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2011-1536x548.png 1536w, https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2011-2048x731.png 2048w, https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2011-1140x407.png 1140w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2017-scaled.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"365\" src=\"https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2017-1024x365.png\" alt=\"\" class=\"wp-image-862\" srcset=\"https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2017-1024x365.png 1024w, https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2017-300x107.png 300w, https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2017-768x274.png 768w, https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2017-1536x548.png 1536w, https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2017-2048x731.png 2048w, https:\/\/www.henrylahr.com\/wp-content\/uploads\/2026\/09\/KDE_vs_Gaussian_2017-1140x407.png 1140w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>The full paper is available at SSRN (this version: 22 September 2026). Traditional stock price synchronicity measures are based on the coefficient of determination (R-squared) from a linear market model and therefore capture only dependence explained by linear correlation. We develop a measure of non-Gaussian stock price synchronicity based on mutual information. It is defined &hellip; <\/p>\n<p><a class=\"more-link btn\" href=\"https:\/\/www.henrylahr.com\/?p=860\">Continue reading<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-860","post","type-post","status-publish","format-standard","hentry","category-papers","nodate","item-wrap"],"_links":{"self":[{"href":"https:\/\/www.henrylahr.com\/index.php?rest_route=\/wp\/v2\/posts\/860","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.henrylahr.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.henrylahr.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.henrylahr.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.henrylahr.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=860"}],"version-history":[{"count":1,"href":"https:\/\/www.henrylahr.com\/index.php?rest_route=\/wp\/v2\/posts\/860\/revisions"}],"predecessor-version":[{"id":863,"href":"https:\/\/www.henrylahr.com\/index.php?rest_route=\/wp\/v2\/posts\/860\/revisions\/863"}],"wp:attachment":[{"href":"https:\/\/www.henrylahr.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=860"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.henrylahr.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=860"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.henrylahr.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=860"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}