I'm going to tell you what I think.
First of all, what we are seeing on Merkur is something different from OTC. We either have 1 institutional seller and someone doing arbitrage, or 2 doing arbitrage. The strategy is to sell at a higher price in Oslo and buy back cheaper on OTC. They then have to transfer the shares to Oslo if they want to repeat the cycle. Which could explain why the number of shares in Oslo have been increasing (I think some people mentioned it).
On OTC, the manipulation theory is not very plausible IMO. I think we could be seeing some unfortunate side-effects from market maker activity. I can think of half a dozen reasons why it could be bad to get caught up in a downtrend, like we are. It's even worse for China stocks, and management repeatedly missing target dates. So that's just it. Something we will have to live with. Also, something we should learn from this. Do not trust the volume either. It's mostly market makers matching each other.
You probably haven't noticed this. But roughly 1 1/2 years ago volume on this stock suddenly dropped by more than 60%. Overnight. So that tells you that some market makers stopped making a market in this stock. It's only recently that we saw volume coming back.
