I believe it depends on your broker. As far as MM's buying and selling, they are only required to make the market, which may mean buying shares when a market order is placed.
Of course with no bid, they are certainly under no obligation to purchase them, but they'll usually scoop them up at a fraction of the cost and sell them just below the current Ask whenever anyone wants to buy shares. That's how some here have actually gotten filled at .000099 I believe.
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