Expected move (1 SD)
±$7.17
Expected move calculator
How far is the market pricing a stock to move by expiration? Enter the price, implied volatility and days to expiration.
68% range
$92.83 – $107.17
95% range (2 SD)
$85.67 – $114.33
Try a strategy on this range
Use the range to pick strikes in the options profit calculator.
The formula
Expected move = stock price × implied volatility × √(days to expiration ÷ 365)
With a $100 stock, 25% implied volatility and 30 days left: 100 × 0.25 × √(30 ÷ 365) = ±$7.17. That puts the one-standard-deviation range at $92.83 to $107.17.
What the expected move tells you
It's the market's own estimate of a typical move, read from option prices. Option sellers often place short strikes near or outside it, and buyers use it to judge whether a move they expect is already priced in. It describes the size of a move, not its direction.
It's only the market's price, though. Whether selling or buying that move makes sense on average depends on how much the stock actually moves, its realized volatility. That's what Options Verdict compares.
Questions
How do you calculate the expected move?
Multiply the stock price by implied volatility and by the square root of the time to expiration in years: price × IV × √(days ÷ 365). That's a one-standard-deviation move.
How often does the stock stay inside the expected move?
If prices followed the model exactly, about 68% of the time for one standard deviation and about 95% for two. Real stocks have more big surprises than the model, so the outer range gets broken more often than 5% of the time.
Should I use calendar days or trading days?
Implied volatility is quoted on calendar time, so this calculator uses calendar days ÷ 365. Some platforms use trading days ÷ 252 instead. The two give similar answers.
Where do I find implied volatility?
Your broker's option chain shows it for each strike and expiration. Use the at-the-money implied volatility for the expiration you care about.