{"id":173568,"date":"2025-11-08T17:00:00","date_gmt":"2025-11-08T17:00:00","guid":{"rendered":"https:\/\/cryptonews.com\/fr\/?p=173568"},"modified":"2025-11-08T13:12:42","modified_gmt":"2025-11-08T13:12:42","slug":"polymarket-volumes-artificiels-columbia","status":"publish","type":"post","link":"https:\/\/cryptonews.com\/fr\/news\/polymarket-volumes-artificiels-columbia\/","title":{"rendered":"Les chercheurs de Columbia accusent Polymarket de manipuler ses volumes"},"content":{"rendered":"<p class=\"wp-block-paragraph\">Alors que les march\u00e9s de pr\u00e9diction s\u00e9duisent un public plus large, une \u00e9quipe de Columbia publie un travail qui remet en cause une partie de l&rsquo;activit\u00e9 sur Polymarket. Le c\u0153ur de leur th\u00e8se tient en peu de mots : une part significative du volume viendrait de <strong>wash trading<\/strong>, ces allers-retours factices qui gonflent l&rsquo;impression de liquidit\u00e9. Le papier n&rsquo;est pas encore relu par les pairs, mais il pose des questions qui comptent pour les traders comme pour les r\u00e9gulateurs. <\/p><h2 class=\"wp-block-heading\">Ce que montre l&rsquo;\u00e9tude<\/h2><span class=\"replacer\"><\/span><p class=\"wp-block-paragraph\">Les auteurs observent une pouss\u00e9e d'\u00a0\u00bb\u00e9changes artificiels\u00a0\u00bb \u00e0 partir de <strong>l&rsquo;\u00e9t\u00e9 2024<\/strong>, avec des pics mensuels \u00e9lev\u00e9s, puis un reflux partiel avant une nouvelle hausse en octobre 2025. En cumul, ils estiment qu&rsquo;environ <strong>un quart du volume<\/strong> sur trois ans serait du wash trading. Le message de l&rsquo;\u00e9tude n&rsquo;est pas \u00ab\u00a0tout est faux\u00a0\u00bb, mais \u00ab\u00a0une tranche non n\u00e9gligeable est falsifi\u00e9e\u00a0\u00bb.<\/p><p class=\"wp-block-paragraph\">C&rsquo;est assez pour biaiser des m\u00e9triques que beaucoup lisent au premier degr\u00e9, comme la <strong>croissance<\/strong>, la profondeur, ou le taux d&rsquo;adoption.<\/p><figure class=\"wp-block-embed is-type-rich is-provider-twitter wp-block-embed-twitter\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"twitter-tweet\" data-width=\"550\" data-dnt=\"true\"><p lang=\"en\" dir=\"ltr\">Excited to share our new paper estimating the prevalence of wash trading on <a href=\"https:\/\/twitter.com\/Polymarket?ref_src=twsrc%5Etfw\">@polymarket<\/a> <a href=\"https:\/\/t.co\/hWUyTfQ08X\">https:\/\/t.co\/hWUyTfQ08X<\/a> Nice thread on it by coauthor <a href=\"https:\/\/twitter.com\/allensirolly?ref_src=twsrc%5Etfw\">@allensirolly<\/a> <a href=\"https:\/\/t.co\/MbU4d88Qr9\">https:\/\/t.co\/MbU4d88Qr9<\/a><\/p>&mdash; Yash Kanoria (@ykanoria) <a href=\"https:\/\/twitter.com\/ykanoria\/status\/1986624587644170573?ref_src=twsrc%5Etfw\">November 7, 2025<\/a><\/blockquote><script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script>\n<\/div><\/figure><p class=\"wp-block-paragraph\">Dans les d\u00e9tails, l&rsquo;\u00e9quipe s&rsquo;appuie sur une <strong>d\u00e9tection r\u00e9seau<\/strong> plut\u00f4t que sur des indicateurs simples type \u00ab\u00a0m\u00eame adresse qui ach\u00e8te et vend\u00a0\u00bb. L&rsquo;id\u00e9e est de rep\u00e9rer des motifs relationnels entre comptes qui s&rsquo;ach\u00e8tent mutuellement de fa\u00e7on r\u00e9p\u00e9t\u00e9e, \u00e0 des instants et tailles caract\u00e9ristiques.<\/p><p class=\"wp-block-paragraph\">Ce n&rsquo;est pas une accusation juridique. C&rsquo;est une <strong>cartographie de comportements<\/strong> qui, statistiquement, ressemblent \u00e0 de la mise en sc\u00e8ne d&rsquo;activit\u00e9.<\/p><h2 class=\"wp-block-heading\">Pourquoi le volume compte vraiment<\/h2><span class=\"replacer\"><\/span><p class=\"wp-block-paragraph\">Le volume, c&rsquo;est plus qu&rsquo;un chiffre d&rsquo;ego. Il conditionne l&rsquo;ex\u00e9cution et, surtout, la confiance. Sur un order book fin, 100 000$ de volume r\u00e9el n&rsquo;ont pas le m\u00eame sens que 100 000$ d&rsquo;allers-retours st\u00e9riles.<\/p><p class=\"wp-block-paragraph\">Des market makers ajustent leurs spreads sur la rotation per\u00e7ue. Si une portion est gonfl\u00e9e artificiellement, les spreads se resserrent \u00e0 tort et l&rsquo;\u00e9cosyst\u00e8me prend un risque de r\u00e9putation.<\/p><p class=\"wp-block-paragraph\">Le probl\u00e8me est d&rsquo;autant plus d\u00e9licat pour un march\u00e9 de pr\u00e9diction. Ici, le prix encode une <strong>probabilit\u00e9 implicite<\/strong>. Si de faux volumes am\u00e8nent de faux signaux, l&rsquo;utilit\u00e9 m\u00eame du produit s&rsquo;\u00e9rode. <\/p><h2 class=\"wp-block-heading\">Les signaux contradictoires sur l&rsquo;activit\u00e9 r\u00e9elle<\/h2><span class=\"replacer\"><\/span><p class=\"wp-block-paragraph\">Le narratif concurrent, c&rsquo;est celui d&rsquo;une <strong>croissance organique<\/strong> : plus d&rsquo;utilisateurs, plus de march\u00e9s, plus de mise en sc\u00e8ne m\u00e9diatique autour des \u00e9lections et des grands \u00e9v\u00e9nements. Ce narratif peut \u00eatre vrai et coexister avec des volumes artificiels. Ce n&rsquo;est pas exclusif.<\/p><p class=\"wp-block-paragraph\">La question est la <strong>proportion<\/strong> et l&rsquo;effet net sur la qualit\u00e9 d&rsquo;ex\u00e9cution.<\/p><figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"859\" src=\"https:\/\/cimg.co\/wp-content\/uploads\/sites\/3\/2025\/11\/08130818\/img-2025-11-08-a-14.07.14-1024x859.jpg\" alt=\"\" class=\"wp-image-173616\" srcset=\"https:\/\/cimg.co\/wp-content\/uploads\/sites\/3\/2025\/11\/08130818\/img-2025-11-08-a-14.07.14-1024x859.jpg 1024w, https:\/\/cimg.co\/wp-content\/uploads\/sites\/3\/2025\/11\/08130818\/img-2025-11-08-a-14.07.14-300x252.jpg 300w, https:\/\/cimg.co\/wp-content\/uploads\/sites\/3\/2025\/11\/08130818\/img-2025-11-08-a-14.07.14-768x644.jpg 768w, https:\/\/cimg.co\/wp-content\/uploads\/sites\/3\/2025\/11\/08130818\/img-2025-11-08-a-14.07.14-1536x1288.jpg 1536w, https:\/\/cimg.co\/wp-content\/uploads\/sites\/3\/2025\/11\/08130818\/img-2025-11-08-a-14.07.14-450x377.jpg 450w, https:\/\/cimg.co\/wp-content\/uploads\/sites\/3\/2025\/11\/08130818\/img-2025-11-08-a-14.07.14.jpg 1572w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\"><\/figure><p class=\"has-text-align-center wp-block-paragraph\">Lien de l&rsquo;\u00e9tude : <a href=\"https:\/\/papers.ssrn.com\/sol3\/papers.cfm?abstract_id=5714122\"><em>https:\/\/papers.ssrn.com\/sol3\/papers.cfm?abstract_id=5714122<\/em><\/a><\/p><p class=\"wp-block-paragraph\">Certains analystes mettent en avant la progression des comptes actifs et des mises nettes comme contre-poids. Tr\u00e8s bien. Mais si 20% \u00e0 60% d&rsquo;un mois donn\u00e9 rel\u00e8vent d&rsquo;un pattern d&rsquo;auto-n\u00e9gociation, l&rsquo;interpr\u00e9tation des courbes doit changer.<\/p><p class=\"wp-block-paragraph\">Les m\u00e9triques comme les <strong>d\u00e9p\u00f4ts nets en dollars<\/strong>, les cash-outs, ou les profits utilisateurs agr\u00e9g\u00e9s apr\u00e8s frais, deviennent plus pertinentes. <\/p><h2 class=\"wp-block-heading\">Ce que cela implique pour Polymarket et les r\u00e9gulateurs<\/h2><span class=\"replacer\"><\/span><p class=\"wp-block-paragraph\">Pour Polymarket, l&rsquo;enjeu n&rsquo;est pas seulement marketing. Il est <strong>op\u00e9rationnel et r\u00e9glementaire<\/strong>. Aux \u00c9tats-Unis, la fronti\u00e8re entre march\u00e9 de paris, produit d\u00e9riv\u00e9 et valeur mobili\u00e8re est d\u00e9j\u00e0 complexe. Ajouter une suspicion d&rsquo;activit\u00e9 artificielle invite \u00e0 un <strong>surcro\u00eet de vigilance<\/strong>.<\/p><p class=\"wp-block-paragraph\">La plateforme peut r\u00e9agir en renfor\u00e7ant la surveillance comportementale et en publiant un <strong>tableau de bord<\/strong> au sujet de son volume, auditable par des tiers. Cela co\u00fbte, mais c&rsquo;est n\u00e9cessaire pour un <a href=\"https:\/\/cryptonews.com\/fr\/news\/polymarket-retour-usa-marches-sportifs\/\">statut durable<\/a>.<\/p><p class=\"wp-block-paragraph\">En attendant, traders comme plateformes ont tout int\u00e9r\u00eat \u00e0 agir comme si la conclusion \u00e9tait au moins partiellement vraie. Mieux vaut s&rsquo;aligner maintenant sur des <strong>standards de transparence<\/strong> que d&rsquo;attendre une injonction. Le pari le plus payant \u00e0 long terme, ici, c&rsquo;est la <strong>confiance<\/strong>.<\/p><hr class=\"wp-block-separator has-alpha-channel-opacity\"><p class=\"wp-block-paragraph\">Pour aller plus loin sur le sujet :<\/p><ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/cryptonews.com\/fr\/news\/avis-polymarket-gagner-cryptos-tutoriel\/\">Avis Polymarket : comment y gagner des cryptos ? Tutoriel d\u00e9taill\u00e9<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/cryptonews.com\/fr\/news\/polymarket-limitless-adoption-web3-marches-predictifs\/\">Polymarket, Limitless, Myriad, Kalshi : l&rsquo;avenir de l&rsquo;adoption grand public dans le Web 3 ?<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/cryptonews.com\/fr\/news\/x-polymarket-partenariat-marches-predictifs-paris-crypto\/\">X fait de Polymarket son partenaire Web 3 pour lancer sur son r\u00e9seau des march\u00e9s pr\u00e9dictifs<\/a><\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Alors que les march\u00e9s de pr\u00e9diction s\u00e9duisent un public plus large, une \u00e9quipe de Columbia publie un travail qui remet en cause une partie de l&rsquo;activit\u00e9 sur Polymarket. Le c\u0153ur de leur th\u00e8se tient en peu de mots : une part significative du volume viendrait de wash trading, ces allers-retours factices qui gonflent l&rsquo;impression de [&hellip;]<\/p>\n","protected":false},"author":708,"featured_media":173573,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[8,1],"tags":[],"editors":[2551],"sponsored_companies":[],"class_list":["post-173568","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-altcoin-news","category-news","editors-julien-leroy"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.9 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Les chercheurs de Columbia accusent Polymarket de manipuler ses volumes<\/title>\n<meta name=\"description\" content=\"Polymarket serait gonfl\u00e9 par des volumes artificiels selon Columbia University, qui 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