It's hard to prove a link that someone knows something about a competitor's company and thus counting on the stock to tank. However, depending on the prosecutio

It's hard to prove a link that someone knows something about a competitor's company and thus counting on the stock to tank. However, depending on the prosecution they may charge the miscreant with other crimes e.g. possession of trade secrets. FWIW the CIO of Equifax found out about the Equifax breach obliquely and was charged with insider trading while the CEO made sone suspicious trades before the press release and was not charged. https://money.cnn.com/2018/03/14/news/companies/equifax-insider-trading/index.html https://money.cnn.com/2018/03/14/news/companies/equifax-insi... As for your last point, I think that's the role of the market speculators and usually the SEC or other enforcement agencies do not take an active role in policing these actions unless there is compelling evidence that a crime has been committed.