Market Maker Inventory
Market maker inventory refers to the current holdings of an underlying asset and its derivatives held by a market maker to facilitate trading. Because market makers must provide liquidity on both sides of the market, they often accumulate inventory that they must manage to minimize risk.
This inventory reflects the net directional bias and the aggregate delta, gamma, and vega exposure of the market maker's book. Managing this inventory is a constant balancing act between earning the bid-ask spread and avoiding adverse selection.
When market maker inventory becomes lopsided, they may adjust their quotes or trade the underlying asset to bring their risk back within limits. This activity can have a profound impact on the market, as the market maker's need to hedge their inventory can drive price trends.
Analyzing market maker inventory is a key component of understanding the supply and demand dynamics in professional trading venues.