Dealer Hedging Explained: Why Market Makers Must Trade

The Dealer's Problem

A market maker's job is to provide liquidity — to stand ready to buy and sell options so that other traders can execute their strategies. When a market maker sells you a call option, they collect the premium. But now they are exposed: if the stock goes up, they lose money on that call.

Market makers do not want to make directional bets. They want to collect the spread between the bid and ask price — a small, consistent profit on every trade. To eliminate the directional risk of the options they have sold, they must delta hedge.

What Delta Hedging Looks Like

Delta measures how much an option's value changes for a $1 move in the stock. If a dealer has sold a call with a delta of 0.50, they need to buy 50 shares to offset the directional exposure. If the stock moves and the delta becomes 0.60, they need to buy 10 more shares. If it drops to 0.40, they sell 10 shares.

This constant adjustment — buying and selling shares to match the changing delta of their options portfolio — is delta hedging. It happens continuously throughout the trading day.

Why This Moves Markets

Individual dealer hedging adjustments are small. But collectively, options dealers hold positions representing billions of dollars in gamma exposure. When the entire dealer community needs to hedge in the same direction at the same time, the aggregate flow is enormous.

This is mechanical flow — it happens regardless of the dealer's view on the market, regardless of the news, regardless of fundamentals. When the math says hedge, they hedge.

The Assumption You Need to Understand

Hedging Is Not Instant

Dealers do not hedge every tick. They have internal risk limits, hedging schedules, and discretion about exactly when and how they adjust. Some hedge continuously. Some hedge in batches. Some use futures instead of shares. The aggregate picture smooths these differences, but the timing and method of hedging varies by firm.