The cryptocurrency market is too big and you can't affect it by spreading some news in this forum especially if you are not a know member.
To affect the market you have to be a well known person and have millions of followers.
Besides, there are many experts who are able to tell whether the news are true or false and certainly people will believe them.
A person alone cannot affect the price of bitcoin or other cryptocurrencies, but FUD has a way to spread like a virus, a person creates a thread with negative information about bitcoin and then 5 more people begin to spread that information then all of those that read that info begin to do the same and finally this has a big effect on the price, so I think it is a mistake to underestimate FUD, since it is an effective tool to make the price to go down.