He wields enough power in his position that he doesn't need anyone to bring it about.
What has he done / is he doing that's illegal? Can no one post on social media that they are interested in a stock?
We're all just getting front row seats to the show.
This is called a pump and dump scam, and is fraud. It hurts real people. It's why the regulatory framework exists, to protect naive investors from predatory ones, and ensure that misconduct doesn't overwhelm the valuable functions of the market.
An old adage used to describe the law in this context: "you can be a pig, but don't be a hog".
He has the position and the funds to make the play himself.
Maybe we really do need a little dance with authoritarianism here to remind people what that is.
Even its allies aren't free of government interference from the US.
It's also a national pastime to crap on the government. Are you not aware that thousands of reporters and millions of people embarrass the US government every day?
The release of "Collateral Murder" damaged public opinion of the US invasion of Iraq and US foreign policy in general. If journalists embarrass the US government by telling them their nose looks funny, Assange embarrassed them by pulling their pants down at the half time show at the Superbowl.