In a dramatic legal confrontation that could have far-reaching implications in the world of cryptocurrency investments, Arthur Copstein has filed a lawsuit against Mathias Arne Paul Jung and his family, accusing them of fraud and misappropriation of funds. The complaint was lodged on December 17, 2024, in the Superior Court of California, County of San Francisco. Copstein's allegations are severe, claiming that Jung and his family conspired to loot millions from a crypto-asset fund they co-managed.
The case revolves around a crypto-asset fund established in 2020 by Copstein and his long-time friend Mathias Arne Paul Jung. According to the complaint, both were general partners in this venture with Copstein responsible for raising capital while Jung handled day-to-day trading activities. The plaintiff asserts that he successfully raised 181 Bitcoin for the fund and maintained communications with limited partners based on information provided by Jung. However, Copstein alleges that instead of trading as promised, Jung embezzled funds for personal gain with the help of his family members—Johannes Werner Erik Jung, Hans Frieder Jung, and Sabine Petra Leppe.
Copstein claims that when he sought clarity on fund performance, Jung falsely assured him of an audit while continuing to misappropriate assets. He accuses the defendants of purchasing real estate under family names to hide stolen assets and believes this conspiracy is ongoing. The complaint details how Copstein had to settle claims out-of-pocket with limited partners due to these fraudulent activities which have also damaged his reputation.
The lawsuit outlines multiple causes of action including breach of fiduciary duty, breach of investor agreement, fraud, conversion, voidable transfer under the Uniform Voidable Transactions Act, common law equitable indemnity, money had and received claims against all defendants. Copstein seeks compensatory damages exceeding $15 million along with punitive damages and various forms of equitable relief such as accounting and restitution.
Representing Arthur Copstein are attorneys Michael Burshteyn and Kristin O’ Carroll from Greenberg Traurig LLP. The case is presided over by judges at the Superior Court of California in San Francisco under Case ID: 24-620719.