Some kind of credible evidence
It may be hard to ever know, but at least there should be significant reason to believe it.
They should have spent at least 10k USD (inflation adjusted based on 12/2023) on this effort.
Goals include: influencing media reporting so they can profit elsewhere
Excluded: manipulation by governments, individuals, charities, etc for non-immediately money-related reasons.
To qualify, the manipulation should be done here with no intention to make mana, and in fact with a very high probability of losing mana, but with the intention of profiting in real world money or profit directly, via other markets (either prediction or real)
If the manipulation here is to curry favor with a politician, and then only later, make money/profit off of that, it doesn't count.
Would qualify:
lowering prices here, hoping that international prediction markets will also lower (incorrectly) so that the company can buy YES there and profit when the price returns to a valid one
Not qualify
lowering prices here to flatter a politician, with or without their knowledge, in hope the politician will separately grant them a favor which would lead to money
manipulating prices to demonstrate power, to get hired at a job, to make a salary [the manipulation should be part of a concrete set of planned concrete monetary transactions designed to lead to profit]