April 2026 saw notable methodological convergence in the academic study of informed trading on decentralized prediction markets. Three approaches surfaced almost simultaneously: Mitts and Ofir (2026) apply a composite screen to over 210,000 wallet-market pairs; Gomez-Cram et al. (2026) apply an event-level sign-randomization test to Polymarket's complete transaction history, classifying 3.14% of accounts as "skilled winners" and separately flagging 1,950 accounts as "insiders" via a lifecycle heuristic; Nechepurenko (2026) develops the Information Leakage Score (ILS) framework, which quantifies per-market information front-loading at an article-derived public-event timestamp. This paper provides a methodological comparison. The central claim is that these are three distinct layers of detection, not competing methods on a single layer. Sign-randomization is best understood as an account-level test of persistent directional skill conditional on opportunity selection -- not a direct test of insider trading, and not a per-market measure. The heuristic insider flag is separate from the skill classifier, applies to a population the classifier excludes by design, and has unknown precision. The Polymarket sample pools politics, sports, crypto, and other categories with different information technologies, so a platform-wide "skilled winner" classification is mechanism-ambiguous. The January 2026 U.S.-Venezuela operation cluster, where the DOJ indictment of Master Sergeant Gannon Van Dyke provides a rare external enforcement benchmark, illustrates how the layers stack: lifecycle heuristics identify suspicious accounts; legal investigation addresses non-public-information possession; per-market scoring would quantify how much information was leaked into each contract. A combined pipeline gains in precision because each layer filters a different dimension.

翻译：2026年4月，学术界对去中心化预测市场中知情交易的研究呈现出显著的方法论融合。几乎同时出现了三种方法：Mitts和Ofir（2026）对超过21万个钱包-市场配对应用了复合筛查；Gomez-Cram等人（2026）对Polymarket的完整交易历史应用了事件级符号随机化检验，将3.14%的账户归类为"技能型赢家"，并基于生命周期启发式方法单独标记了1950个账户为"内部人士"；Nechepurenko（2026）提出了信息泄露评分（ILS）框架，该框架以文章导出的公共事件时间戳为基础，量化了每个市场的信息前置加载程度。本文提供了方法论比较。核心观点是，这三种方法是检测的三个不同层次，而非同一层级的竞争性方法。符号随机化检验应被理解为一种账户级别的检验，用于考察在机会选择条件下的持续性方向性技能，而非对内部交易的直接检验，也不是市场层面的度量指标。启发式内部人士标记与技能分类器相互独立，适用于分类器在设计上排除的群体，且其精度未知。Polymarket样本融合了政治、体育、加密货币及其他具有不同信息技术的类别，因此平台层面的"技能型赢家"分类存在机制模糊性。2026年1月的美委行动集群，其中美国司法部对甘农·范戴克军士长的起诉提供了一个罕见的外部执法基准，展示了各层次的堆叠方式：生命周期启发式方法识别可疑账户；法律调查处理非公开信息占有问题；市场级评分则将量化每个合约中信息泄露的程度。由于每个层次过滤不同维度，组合流程的精度得以提升。