Roughly, it's illegal only if you have some duty not to trade on it. If you acquired the information without misappropriating it (like overhearing it from stran

Roughly, it's illegal only if you have some duty not to trade on it. If you acquired the information without misappropriating it (like overhearing it from strangers in a normal public bar), then you're free to trade. https://corpgov.law.harvard.edu/2017/01/18/insider-trading-law-after-salman/ https://corpgov.law.harvard.edu/2017/01/18/insider-trading-l... There's no reason for normal corporate training to discuss that element, because an employee who trades their employer's stock based on MNPI has near-certainly misappropriated it. The question of whether a non-employee has misappropriated information is much more complex, though.