To the poster who said the MMs were unloading the "last of their shares"..
That's not how MMs work at all. You don't know anything about market micro-structure.
They always keep a backlog of shares, they have too, SEC rules again. Plus it makes business sense. Their number one objective (from the SEC) is to maintain an orderly market. That's their job. In addition, they are allowed to make money on the spread.
Obviously in a highly volatile (high beta) microcap like ROSG, 'orderly market' needs to be carefully considered. It's not what you think. Spikes are allowed (like the recent one) and they are allowed to make money for themselves on the spread to supply liquidity, on the buy and sell sides.
They have complex algorithms that detect trends and watch the liquidity. As less sellers appear, they are required to sell, as less buyers appear, they are required to buy. You don't see it happen, it's done by a machine in millionths of a sec. The original trading algos from the 1990s came from these early progams the MMs use. The latest ones are amazingly sophisticated. Millions of lines of code.
Now, for ROSG I estimate they keep at least 300k to 500k shares on hold. It's a complex calculation based off of the outstanding float, the beta and about 5 other variables like 10 day moving average of the volume. It will fluctuate a lot, maybe 20-30% over the course of some active trading days, fluctuates maybe only 1-3% on slow days.
Remember, they make their money on the spread between the bid and the ask. When the spread is 1 cent, they really aren't making any money. When it spikes or drops, the spread increases and then they step in, supplying liquidity on the weaker side where needed, and skimming a profit for themselves. They never lose.
Like all trading participants, long or short, they need movement. A stock not moving much is 'dead' money to all, except long term holders who care little for the daily churn.