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Expected Move Calculator
Calculate the expected move and ±1 sigma price range to expiry from spot, volatility and days — or approximate it from an at-the-money straddle price.
Expected move (±1σ)
± $5.73
- Lower bound
- $94.27
- Upper bound
- $105.73
- % move
- 5.73%
±1σ ≈ a 68% chance of finishing within this range by expiry.
How this is calculated
The expected move to expiry is one standard deviation of the underlying's price:
EM = S × σ × √T, with the range S ± EM and % move = EM ÷ S.
There is roughly a 68% chance the price finishes within ±1σ. If you prefer, switch to the straddle method, which approximates EM ≈ 0.85 × the ATM straddle price.
Frequently asked questions
- How is the expected move calculated?
- Expected move ≈ spot × volatility × √(time in years). The price has roughly a 68% chance of finishing within ±1 standard deviation of spot.
- Can I use a straddle price instead?
- Yes. A common approximation is expected move ≈ 0.85 × the at-the-money straddle price for the same expiry.