Cryptocurrencies are increasingly popular. Even people who are not experts have started to invest in these securities, and nowadays, cryptocurrency exchanges process transactions for over 100 billion US dollars per month. In spite of this, many cryptocurrencies have low liquidity, and therefore, they are highly prone to market manipulation. This paper performs an in-depth analysis of two market manipulations organized by communities over the Internet: The pump and dump and the crowd pump. The pump and dump scheme is a fraud as old as the stock market. Now, it got new vitality in the loosely regulated market of cryptocurrencies. Groups of highly coordinated people arrange this scam, usually on Telegram and Discord. We monitored these groups for more than 3 years detecting around 900 individual events. We analyze how these communities are organized and how they carry out the fraud. We report on three case studies of pump and dump. Then, we leverage our unique dataset of the verified pump and dumps to build a machine learning model able to detect a pump and dump in 25 seconds from the moment it starts, achieving the results of 94.5% of F1-score. Then, we move on to the crowd pump, a new phenomenon that hit the news in the first months of 2021, when a Reddit community inflates the price of the GameStop stocks (GME) of over 1,900% on Wall Street, the world's largest stock exchange. Later, other Reddit communities replicate the operation on the cryptocurrency markets. The targets were Dogecoin (DOGE) and Ripple (XRP). We reconstruct how these operations developed, and we discuss differences and analogies with the standard pump and dump. Lastly, we illustrate how it is possible to leverage our classifier to detect this kind of operation too.
翻译:加密密码交换器交易, 通常是在Telegram和Discord上。 尽管如此, 许多加密交易的流动性都很低, 因此他们很容易被市场操纵。 本文深入分析了两个由社区通过互联网组织的市场操纵: 泵和垃圾以及人群泵。 泵和垃圾桶计划与股票市场一样老旧, 是一个骗局。 现在, 它在监管松散的加密证券市场中获得了新的活力。 高度协调的人群组织这个骗局, 通常是在Telegram和Discord上。 尽管如此, 许多加密交易的流动性都很低, 因此他们很容易被市场操纵。 我们分析这些社区是如何组织起来的, 以及他们是如何进行欺诈的。 我们报告三个关于泵和垃圾的案例研究。 然后, 我们利用我们经核实的泵和垃圾的市场的独特数据集来构建一个机器学习模型, 能够从一开始就检测出一个泵和垃圾桶的变价( ) 。 在开始的时候, 高度协调的集团组织这个骗局, 通常在Telegramgram 上安排这个骗局。 。 我们用F1- Stebrial 的操作, 然后在新的游戏中, 开始, 开始, 我们用一个新的游戏中, 开始, 开始, 开始一个游戏中, 我们开始一个游戏中, 开始, 开始一个游戏的运行到一个游戏中, 我们开始, 一个游戏中, 开始, 开始一个游戏中的游戏的游戏中的游戏中的游戏中的游戏的运行。