A perpetuals trading platform called Sunray Finance was hacked on October 30 by an attacker who was able to upgrade a smart contract used by the protocol. They then were able to mint a massive number of the protocol's SUN token — 200 sextillion, to be precise. Then, they cashed out what they were able to, crashing the SUN token price in the process. Ultimately, the attacker made off with about $2.1 million of the Tether stablecoin.
In the process of selling off tokens, an arbitrage bot was able to take advantage of the price difference by selling the rapidly crashing SUN token into a second liquidity pool that apparently went unnoticed by the hacker, and the bot operator also profited around $560,000.