Decision Diagnostics Corp (DECN)

[DrZem]

Investopedia says MM's do hold an inventory

Market-making firms affect prices in several ways. By standing ready to buy and sell stock from the retail and institutional trading community, market makers take the other side of the trade, exposing themselves to fluctuating prices and the market risk that goes with it. They are partially compensated by being able to buy at the bid and sell at the offer. To fully mitigate their exposure, market makers will accumulate or liquidate inventory in anticipation of the market's consensus outlook. Often, this will entail buying or selling in contrast to most public participants in a particular stock or group.