Avi Eisenberg

Avraham Eisenberg, an American DeFi trader operating openly under his own name on Twitter, executed what he described from the start as a “highly profitable trading strategy” against Mango Markets, a Solana-based decentralised exchange, in October 2022. The strategy worked like this: deposit $5 million as collateral; take a massive long position in MNGO/USDC perpetual futures; buy MNGO across the thin oracle sources Mango used to value collateral, pushing the recorded price up roughly thirteen times in a few minutes; against the inflated collateral value, borrow $114 million in other tokens; withdraw and exit.

Eisenberg’s defence was that he had not hacked anything. The Mango Markets contract did exactly what its code instructed it to do. He had simply traded against the contract within the rules the contract enforced. He used a portion of the borrowed funds to vote in a Mango DAO governance proposal that would have let him keep $47 million as a “bug bounty” in exchange for not pursuing further legal action. The DAO approved the proposal — voted in part with his own borrowed tokens.

US federal prosecutors disagreed. Eisenberg was arrested in Puerto Rico in December 2022 and charged with commodities fraud and market manipulation. In April 2024 a New York jury convicted him on three counts. The case set a precedent: the “code is law” defence — that anything a smart contract permits is by definition legal — does not survive contact with US commodities-fraud statute. He is currently serving his sentence and the verdict is on appeal.

Eisenberg matters because his case is the legal benchmark for every future DeFi exploiter who wants to argue that no crime was committed. The framework now exists; subsequent prosecutions cite the precedent.