I am reviewing some market-maker raw data and sometimes I see the following happening. The market-maker quotes an ask price that is below the current bid price (of let's say, the market itself). How is that possible? What is happening?
An important characteristic of the quotes (ask) that are lower than the current bids, is that they are almost always at the same level. So even though the bid and ask are changing through time, these 'flawed' asks always remain on (approximately) the same price level.