The stock market has so much more scale, in money at stake, data, news coverage, experts followup on rumors, etc. it would be relatively harder, and take more potentially traceable effort, to impact pricing with a rumor.

But it almost certainly happens.

So not fundamentally different.

And I just figured out how I would leverage particular kinds of existing credibility, and vulnerability, to do it. But the harder part is making significant bank, while not getting caught. (And spending eternity with your black soul!)