Manipulation is always there. To what degree is always the question. Doesn't matter if a stock is unsolicited or not, there are the ones who control the transactions. They don't do it for free and they make money for doing it and when ever there is money to be made at the control of others, there is manipulation. So, unless one is buying and selling paper shares directly from the company, you will have the programs that are designed to as I've stated before, making the house always winning and that takes manipulation.
But I would say there isn't as much here at low volumes and the level of manipulation changes as it does for any stock depending on many factors including interest amongst individuals and other big money forces upon any industry or company. Even those couple of factors are not all inclusive, it involves many others, but there is always manipulation to some degree.