The Bid/Ask you see here is what the MMs establish. You answered your own question. The MMs see the true retail Buy and Sell offers. They match them up and make margin when they can. It is a timing matter for them. If you don't offer to Buy at their ASK they have all day to decide whether to take you. If you don't offer to Sell at their BID they also have all day. If they keep it spread and people are just under the ASK and just over the BID and the quantities will work for them (not AON, or if it is then within the range needed)... BANG, quick mirror for one of the MMs. Each hopes to make more than the other, so they compete within that range and decide if it is worthwhile or if everyone is willing to wait believing there will soon be a better move. The fewer the MMs the better for them, especially if one MM has not signed on to support the stock (which won't happen without some disclosures by the company).
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