It is an almost 100% indicator of big holders (fianancier/shell vendor etc..) dumping when the share amounts are large. They hire the MM to sell for them, the MM dumps all day and as you said that is them squaring up the sales they transacted. Anyone new to the OTC markets should learn this as it is a very good thing to know.
Understood but interesting we have had a number of days in a row with them and they had substantial volumes. It is odd the system can not reconcile these orders during the day. Cheers