Gamma Trading as a Market Maker
Get out of your own head as the market participant (for now). What is Gamma? Gamma = the rate of change of delta. Think of Delta as the engine of a car and Gamma as the gas pedal. The harder you press the pedal, the faster the engine revs. In options, that means the more gamma you have, the faster delta will change as the stock moves. This means, Delta never stays still. If you're long gamma, for example, you're buying options from me, the trader, your delta will swing a lot as the underlying stock moves. If you're short gamma (from selling options), you're delta exposure will flip against you when the stock moves. You, as the market maker, are always going end up long or short gamma. And this is going to force you always manage your risk with dynamic hedging with stock. ## Gamma Scalping If you're long gamma: - Your position gains delta when the stock rises, and loses deltas when it falls. - So you're buying low, selling high (scalping stock around your option). - You bleed theta (time decay), but can "earn it back" if the underlying moves around enough. I hope this is starting to click into your head on how market makers have a huge impact on the stock... If you're short gamma: - You're forced to sell low, buy high to keep hedged. - That's painful if the stock is volatile. - Your edge here has to come from the premium you collected up front (selling options at high volatility) ## Key Points 1) Gamma is where the real risk sits. Directional risk (delta) can be hedged away instantly with stock. Gamma risk means you'll have to hedge over and over again as delta keeps changing. 2) Time vs movement Long gamma bleed s theta → you must get enough stock movement to cover the decay. Short gamma earns theta → but you must pray the stock doesn't whip around too much. 3) Market Makers Live Off It Market makers don't guess direction. They let their gamma + hedging determine whether they profit. - IF they're long options (long gamma), they make their edge from scalping volatility. - IF they're short options (short gamma), they make their edge by collecting theta and quoting wide enough to survive the hedge pain.