Trading that looks like foreknowledge of the release of fake news would stand out, but purchased based on knowledge that the news was fake would blend in with trades by plenty of other people who simply figured it out quickly.

No it won't, the market is too large. This is not a option opportunity after all.

Someone(s), made a LOT of money today. More than you or I will ever make in a lifetime.

Someone(s) also lost a LOT of money today. Given 2 scenarios: A) A script kiddie had fun with a tweet just for the lolz and it had a short term unintended impact on the Dow. B) There is a nefarious plot by folks who have the no how and infrastructure to pull off a highly risky, illegal trade who couldn't make more money just doing what they normally do.

Yeah, the dumb money lost again, as always.

Understood, but the SEC doesn't investigate every butterfly [1] transaction, and since you're spread wide its a lot more subtle.

[1] Butterfly - a limited risk investment that exploits volatility see [http://en.wikipedia.org/wiki/Butterfly_(options)]

In order to benefit they would have had to sell in very short time.

Yeah, how often do prosecutions actually occur? The market is huge and trades can easily get lost in the noise. Was anyone arrested for trading prior to 9/11?

The only way to figure out who was making trades on the expectation of this hoax would be to find the hacker, which probably means finding who controlled a botnet, which probably means convincing Russia to extradite someone. Good luck.