We present a comprehensive description of Hydra, the largest darknet marketplace in the world until its shutdown in April 2022. We document the main features of Hydra such as dead-drop delivery, feedback and reputation system, escrow, and dispute resolution. Using data scraped from the platform, we quantitatively examine the scale and the structure of the marketplace. We find that it has been highly competitive, geographically covering at least 69% of the Russian population and trading a wide variety of drugs, while also allowing the wholesale trade of drugs and precursors. The dead-drop delivery system used on Hydra was expensive, as the courier costs comprised a substantial proportion of the sale price of drugs on Hydra. We contribute to the research on drug cryptomarkets by studying an unprecedentedly large non-Western marketplace that existed substantially longer than any other known darknet market.

中文翻译：

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Hydra：全球最大暗网市场的教训

我们对 Hydra 进行了全面的描述，这是世界上最大的暗网市场，直至 2022 年 4 月关闭。我们记录了 Hydra 的主要功能，例如死点交付、反馈和声誉系统、托管和争议解决。使用从平台抓取的数据，我们定量检查市场的规模和结构。我们发现它竞争非常激烈，地理上覆盖了至少69%的俄罗斯人口，交易的毒品种类繁多，同时还允许毒品和前体的批发贸易。Hydra 上使用的定点投递系统价格昂贵，因为快递成本占 Hydra 上药品销售价格的很大一部分。我们通过研究一个前所未有的大型非西方市场，该市场的存在时间比任何其他已知的暗网市场都要长得多，从而为毒品加密市场的研究做出了贡献。