Do you have any reasonable explanation how 1m shares transferred to Merkur in 3 weeks?
Of course. DNM and DBB could very well be doing "arbitrage". Selling (shorting) on Merkur and buying back cheaper on OTC. So they would have to transfer shares back to Merkur if they want to repeat the cycle.
The problem with that theory is, I don't see a whole lot of buying on OTC either. Well I do, but it's "fake" market maker volume at the ask IMO.