For quite some time, there has been a seller in the market that...

For quite some time, there has been a seller in the market that hits the IRN bid continually after a trade at the offer price, whether the shareprice is up, down or unchanged.
An example is today when it trades up to 27 / 27.5, almost instantly a seller hits the bid to make it look weaker.

My thoughts are that it is being capped to build a larger stake, but this has been going on for months now. Due to this, I feel that it is someone "feeding" the market.

Can anyone help. I'm still mega bullish but just interested