Is Elon Musk not allowed to say anything ever again? Does the follower size decide whether it was manipulation? Which follower count then? Or which price movement in relative terms?
When a very influential person, who controls billions of dollars, just say crazy stuff to see the price goes up and down , that is manipulation.
There are many rules in the stock market , and such declarations cannot be made freely. People who have privileged or confidential information not released yet to the public cannot just be tweeting about it.
In stock market this kind of behavior is not allowed and he would have face fines.
You took the easiest part out of my comment and repeated it, but left out a statement to the harder part. Elon Musk is probably one of the easier examples when we talk about "influential" and "billions of dollars". But there are many more edge cases where courts have a hard time to draw the line because they would have to shift that line in the next case most likely anyway.
When it is about obvious insider information, of course there are laws and there is no discussion. But in most cases tweets or info that gets spread is a lot more on the edge. There have been many cases where executives or people closely related to them sold shares or bought shares before some info was made public. Guess what, nobody could prove that at the point in time when sales or purchases were made, the seller or buyer was already aware of that info.
Some of the stuff seems obvious, and some of the stuff is on the edge. The few cases where obvious market manipulation gets caught or fined are not the ones that dominate our global markets. It is mostly the ones that go undetected because it's almost impossible to prove those cases.
And again, where does true manipulation start and where does it end? The easy cases aren't really that interesting.