Max pain, explained
Max pain is the price at which the largest total value of open options contracts would expire worthless — the price that inflicts the most "pain" on option buyers as a group.
How it is calculated
For every strike, you sum what all open calls and puts would be worth if the stock settled exactly there. The strike where that total payout is smallest is max pain. It is arithmetic over open interest, not a prediction model.
Why price sometimes drifts toward it
Market makers who sold those options hedge continuously. As expiry nears and time value collapses, that hedging tends to dampen moves away from the heaviest open interest. The effect is real but weak — it is a gravitational pull, not a rail.
When it matters and when it does not
The pull is strongest in the last days before a monthly expiry on a liquid name with concentrated open interest. It is close to meaningless right after a new cycle opens, or when news is repricing the stock faster than dealers can hedge.
How we show it
We publish max pain next to the current price so the gap is visible at a glance. A wide gap late in an expiry cycle is the setup worth noticing; the same gap on the first day of a cycle usually is not.