GMX is a decentralized cryptocurrency exchange that boasts zero price impact trades. On most exchanges, users have to contend with slippage: a difference between the price of a token when the user goes to enter the trade and the price when the trade is executed. A sufficiently large trade can itself cause slippage, particularly with crypto assets with lower liquidity.A whale was able to take advantage of this “feature” by taking large positions in AVAX, the token belonging to the Avalanche blockchain, which has relatively low liquidity compared to larger tokens like Bitcoin or Ether. The whale then manipulated the price by making large trades on a centralized exchange, taking an estimated profit of between $400,000 and $450,000 after fees.Some had publicly expressed concerns about the possibility of such an exploit earlier in September: Taureau, a founder of another decentralized exchange, had outlined the possibility of an exploit like this on a podcast episode on September 1.GMX responded to the incident by capping the size of positions that users can take on AVAX. Another project, MM.Finance, announced they would be pausing order execution on their MadMex platform, which is a fork of GMX.

Total loss estimated at $400,000.