What Is the Expected Move?

The expected move is the market's estimate of how much a stock's price will change over a specific period. It's derived directly from option prices and represents a one standard deviation move — meaning the stock is expected to stay within this range about 68% of the time.

The Formula

Expected move = Stock price × IV × √(DTE / 365)

Where:

  • Stock price = current share price
  • IV = annualized implied volatility (as a decimal)
  • DTE = days to expiration

    • Example: AAPL at $195, IV of 28%, 30 days to expiration.

    Expected move = $195 × 0.28 × √(30/365) = $195 × 0.28 × 0.2866 = $15.65

    This means the market expects AAPL to trade between $179.35 and $210.65 over the next 30 days, with about 68% probability.

    The Straddle Shortcut

    For earnings plays, there's an even simpler method: the ATM straddle price approximates the expected move for the current expiration.

    How it works: Add the ATM call price and ATM put price for the nearest expiration that captures the event.

    Example: NVDA reports earnings tomorrow. The ATM $900 call costs $32 and the $900 put costs $28. The straddle costs $60.

    The market expects NVDA to move about $60, or roughly 6.7%, by expiration. For a more precise estimate, multiply the straddle by 0.85: $60 × 0.85 = $51.

    The 0.85 multiplier adjusts for the fact that the straddle includes some time value beyond just the expected move.

    Expected Move for Different Timeframes

    | Timeframe | Formula Shortcut | DailyStock × IV / √252 WeeklyStock × IV / √52 MonthlyStock × IV / √12 | Custom (N days) | Stock × IV × √(N/365) |

    Quick daily move for SPY:

    SPY at $540, VIX at 18: Daily expected move = $540 × 0.18 / 15.87 = $6.12

    This tells you that an $6 daily move in SPY is "normal" at current volatility. Moves of $12+ (two standard deviations) are unusual. Moves of $18+ (three standard deviations) are extreme.

    Using Expected Move for Strike Selection

    For premium sellers: Sell strikes outside the expected move. If the expected move is $15, selling a put $18 below the current price gives you cushion beyond what the market expects.

    For credit spreads: Place the short strike at or beyond one standard deviation (the expected move boundary). This gives roughly a 68-84% probability of the short strike expiring worthless.

    For iron condors: Place short strikes at one standard deviation on each side. This creates a range that the stock is expected to stay within about 68% of the time.

    Expected Move Around Earnings

    Before earnings, the expected move is critically important:

  • Calculate the straddle price for the weekly expiration covering earnings
  • Multiply by 0.85 for the expected move
  • Compare to the stock's actual earnings moves from prior quarters

    • If the expected move is $8 but the stock has only moved $5 on average over the last 8 earnings, the market may be overpricing the event — favoring premium sellers. If past moves averaged $12 but the current expected move is only $8, options might be underpricing the event — favoring buyers.

    Limitations

    The expected move assumes a normal distribution of returns. In reality, stock returns have fat tails — large moves occur more frequently than a bell curve predicts. The expected move captures 68% of outcomes, but the remaining 32% includes some extreme moves that can be multiples of the expected range.

    Never treat the expected move as a hard boundary. It's a probability-weighted estimate, not a guarantee.

    OptionsPilot displays strike-level premiums and probabilities, making expected move analysis a natural part of your pre-trade process rather than a separate calculation.