Market Maker¶
OVERVIEW¶
A market maker is a registered dealer that continuously posts both bid and ask quotes for a security, earning the bid-ask spread in exchange for providing immediate liquidity. This allows other market participants to buy or sell without waiting for a matching counterparty.
Note
Without market makers, traders would submit limit orders and wait indefinitely for another participant to take the other side — markets would be illiquid, spreads would be enormous, and price discovery would be erratic.
HOW MARKET MAKING WORKS¶
Market maker profit is derived entirely from the spread, multiplied across volume:
SPY Example: A market maker posts a bid of $521.48 and an ask of $521.50 — a $0.02 spread. At 200M shares of average daily volume with a 20% fill rate (40M shares), that spread earns $800,000 per day before hedging costs.
AAPL Options Example: A market maker posts $2.35 bid / $2.45 ask on weekly options, earning $0.10 ($10 per contract) on every round trip.
Risk Management¶
Market makers manage three risk types in real time:
| Risk Type | Description | Mitigation |
|---|---|---|
| Delta Risk | Net directional exposure from inventory | Continuously hedged via the underlying |
| Gamma Risk | Exposure to large, sudden price moves that overwhelm delta hedging | Highest near expiration; managed through position sizing |
| Inventory Risk | Holding too many shares or contracts on one side before finding the other | Quote adjustment and spread widening |
TYPES OF MARKET MAKERS¶
| Type | Description |
|---|---|
| NYSE Designated Market Makers (DMMs) | Assigned to specific stocks. Obligated to maintain fair and orderly markets, absorb imbalances at open and close, and quote within mandated spread maximums. |
| Nasdaq / OTC Market Makers | Competing firms (Citadel Securities, Virtu, Jane Street) post competing quotes. The best bid and offer across makers forms the NBBO (National Best Bid and Offer). |
| Options Market Makers | Required to post two-sided markets on every listed strike and expiration. Their delta-hedging activity is a significant source of intraday equity volume. |
HOW TO USE¶
Understanding market maker behavior explains several phenomena observable in the Tapeboard terminal:
Options Pinning As expiration approaches, market makers who sold options are short gamma. They hedge by selling the underlying when it rises and buying when it falls — creating magnetic pull toward the strike with the highest open interest (max pain).
Tip
Use the Open Interest panel in Tapeboard to identify where market maker hedging pressure concentrates near expiration.
Spread Widening When a stock halts on news, spreads widen dramatically at reopening because market makers face higher inventory risk with incomplete information.
Note
Crossing a wide spread immediately after a halt is expensive. Monitor the bid-ask spread column in Tapeboard before placing orders following a halt event.
Payment for Order Flow Retail brokers route orders to market makers in exchange for payment. The market maker profits by filling retail orders against their inventory at prices slightly worse than the NBBO.
LIMITATIONS AND COMMON MISCONCEPTIONS¶
| Misconception | Reality |
|---|---|
| Market makers are neutral intermediaries | They take directional views on inventory and adjust quotes accordingly |
| Spread changes signal targeted manipulation | Spread changes are overwhelmingly explained by ordinary inventory management |
| Price prints on the bid or ask indicate coordinated moves | These reflect normal quote adjustments based on inventory position |
| Dark pools are used to manipulate price | Dark pools exist partly to let institutions trade around market maker spreads, not in them |
Note
A market maker long a large block of calls will shade their ask higher to discourage more buying, and lower their bid to encourage sellers who would offset their position. This is standard inventory management, not manipulation.