[maest]

IANAL, but it strikes me as 100% illegal for Twitter to trade on their tweets before they are released (at least for the class of tweets which contain corporate announcements - tweets from e.g. the persident might be treated differently).

Some of those tweets can be resonably be construed as being MNPI, so trading on it before it's published on the platform is most likely illegal.

Can newspapers/journalists trade on a piece of news before they break it?