Whale with high leverage long ARC and suffer a loss of $8.2 million, DeFi perpetual contract liquidity risk reappears

On February 26, a crypto whale engaged in high leverage trading on the decentralized derivatives platform Lighter’s ARC perpetual contract market, ultimately incurring approximately $8.2 million in losses. The platform disclosed that the trader continuously added to long positions over several days, causing the open interest in ARC contracts to rise to around $50 million, forming a clear hedge against short positions held by about 600 traders and market makers.

On Wednesday evening Eastern Time, the price of ARC experienced downward volatility. Large long positions began to slip and triggered chain liquidations. About $2 million worth of positions were forcibly settled on the order book first, with remaining positions subsequently transferred to the Liquidity Provider Pool (LPP) for risk management. As the market continued to weaken, the platform activated its Automatic Deleveraging (ADL) mechanism, partially reducing some profitable short positions to ensure smooth liquidation processes.

During the extreme volatility, the LPP briefly absorbed about 200 million ARC tokens, worth approximately $14.7 million, before gradually reducing risk exposure as the price further declined. Due to ARC’s isolated risk pool design, the actual loss to liquidity providers was limited to around $75,000, while the short traders hedging these positions realized significant gains.

Lighter later announced enhanced risk control parameters, including setting the maximum open interest for ARC trading pairs to $40 million and allocating about $100,000 in dedicated USDC liquidity. Once liquidity is exhausted, the system will automatically switch to the ADL strategy to reduce the risk of DeFi perpetual contract liquidations and systemic shocks.

This incident highlights the structural fragility of decentralized derivatives markets in low-liquidity assets. Previous on-chain cases have shown that large capital concentrations can amplify price volatility, impacting liquidation mechanisms and the stability of funding pools. For participants concerned with DeFi leverage trading risks, on-chain liquidation mechanisms, and auto-deleveraging models, this whale liquidation event in ARC provides an important signal regarding liquidity depth and risk isolation design.