Autodeleveraging (ADL) is a last-resort loss socialization mechanism for perpetual futures venues. It is triggered when solvency-preserving liquidations fail. Despite the dominance of perpetual futures in the crypto derivatives market, with over \$60 trillion of volume in 2024, there has been no formal study of ADL. In this paper, we provide the first rigorous model of ADL. We prove that ADL mechanisms face a fundamental \emph{trilemma}: no policy can simultaneously satisfy exchange \emph{solvency}, \emph{revenue}, and \emph{fairness} to traders. This impossibility theorem implies that as participation scales, a novel form of \emph{moral hazard} grows asymptotically, rendering `zero-loss' socialization impossible. On the positive side, we show that three classes of ADL mechanisms can optimally navigate this trilemma to provide fairness, robustness to price shocks, and maximal exchange revenue. We analyze these mechanisms on the Hyperliquid dataset from October 10, 2025, when ADL was used repeatedly to close \$2.1 billion of positions in 12 minutes. By comparing production ADL to transparent benchmark allocations, we find that Hyperliquid's production algorithm overshot the minimum trader profit haircut required to cover the shortfall. Our methodology suggests the excess profits lost by profitable traders is between \$45.0M and \$51.7M. In terms of the positions liquidated, this corresponds to roughly \$653.6M of positions being closed. This comparison also suggests that Binance overutilized ADL far more than Hyperliquid. Our results show both theoretically and empirically that optimized ADL mechanisms can dramatically reduce losses of trader profitability while maintaining exchange solvency.

翻译：自动去杠杆化（ADL）是永续期货交易场所的最后损失社会化机制，当维持偿付能力的清算失败时触发。尽管永续期货在加密货币衍生品市场占据主导地位（2024年交易量超过60万亿美元），但尚未有关于ADL的正式研究。本文首次建立了ADL的严谨模型，证明了ADL机制面临根本性的"三难困境"：任何策略都无法同时满足交易所的偿付能力、收入和对交易者的公平性。该不可能性定理意味着，随着参与规模扩大，一种新型的道德风险会渐近增长，使得"零损失"社会化成为不可能。从积极角度看，我们证明三类ADL机制能够最优地应对这一三难困境，提供公平性、价格冲击鲁棒性和交易所收入最大化。我们使用2025年10月10日的Hyperliquid数据集分析了这些机制，当时ADL在12分钟内被反复用于平仓21亿美元头寸。通过对比实际ADL操作与透明基准分配方案，发现Hyperliquid的生产算法超出了覆盖资金缺口所需的最小交易者利润削减幅度。我们的方法表明盈利交易者损失的超额利润在4500万至5170万美元之间，按被清算头寸计算，相当于约6.536亿美元头寸被平仓。对比还显示币安对ADL的过度使用程度远高于Hyperliquid。我们的研究从理论和实证两方面证明，优化的ADL机制能在维持交易所偿付能力的同时，显著降低交易者盈利能力损失。