Social-media disinformation affecting financial markets has been addressed under securities laws. In 2015, the Securities and Exchange Commission warned the public about social media fraudsters working to manipulate the market, noting some recent actions it had initiated.
In one case arising in 2013, a Scottish man’s false tweets caused sharp drops in the stock prices of two companies. The case was settled in 2019, when he agreed to pay back profits and prejudgment interest totaling $217. (The SEC noted he may have mistimed his own transactions, limiting his profits.)
In another case, the commission charged a Canadian couple with using social media to boost stock prices on stocks they owned. The couple was fined $3.7 million, representing the profits they had made, plus $300,000 in penalties.