BitMEX's March 12 Outage: Accidental Circuit Breaker or Fatal Flaw?

On March 12, 2020, Bitcoin's price plummeted from $7,900 to $3,600 in just 24 hours, causing a cascade of liquidations across derivatives venues. At the center of this storm was BitMEX, an exchange that had pioneered perpetual swaps and defined the industry's architecture.

BitMEX's matching engine went dark for about 25 minutes, which may have interrupted a self-reinforcing liquidation spiral and prevented Bitcoin from trading lower. The outage was an operational failure, but it functioned like a circuit breaker, stopping the cascading sell-off in its tracks.

The problem lay with BitMEX's inverse contracts, where traders posted Bitcoin as margin on Bitcoin-denominated positions. When the price tanked, the value of every user's collateral fell in unison, accelerating liquidations and draining the exchange's insurance fund.

Bybit, a rival exchange, seized the opportunity to innovate and adapt. It offered USDT-margined perpetuals, which insulated traders from the collateral feedback loop, and focused on creating a smoother trading experience.