Imagine Company X' stock price is $400/share. Can two individuals (owning shares of this company) conspire against it by selling/buying their shares at $1 by the end of the day so that the "closing price" is at $1? (and therefore the news will talk about the shares plummeting for this companay...).  

Is this technically possible? Are there any protections for this sort of behaviour? Has it occurred before?

Thanks,
Cracon