How max pain is calculated
- For each possible closing strike, add up what every open call and put would be worth at expiration.
- The strike with the smallest total payout to option holders is max pain.
- It uses open interest, which updates once a day, so max pain moves day to day.
Why price sometimes drifts toward it
Dealers who sold options hedge with stock. As expiration nears, that hedging can pull price toward strikes with heavy open interest. The effect is strongest in liquid names on big expiration days and weakest when news hits.
Limits to keep in mind
- Max pain ignores who actually holds the options and how they are hedged.
- News, earnings and macro data override it easily.
- Use it as context next to gamma walls and the trend, not as a trade signal.