Ryan Choi, an associate of Andrew Left from Citron Research, has agreed to pay $1.8 million to settle charges brought by the U.S. Securities and Exchange Commission (SEC). The SEC accused Choi of negligently engaging in a scheme to defraud readers of Citron Research through misleading social media posts. The settlement comes in the wake of allegations that Choi, who was responsible for preparing the company's tweets, claimed they could significantly impact stock prices with just a single tweet. The case highlights ongoing scrutiny of social media's influence on financial markets.