ATM at expiry
The call expires worthless. You keep the entire premium — the best case for a short call.
- Expiry P&L
- 10
- Max gain
- 10
Short Call Put Calculator
Sell a naked call or put, chart the expiry payoff, and slide spot, time, and implied vol to see theoretical P&L before expiry.
Upside is the premium; a short call has unlimited downside. Click Calculate to solve implied vol, then use the sliders. Figures are theoretical and for information only.
Type a symbol, then Load or leave the field. Spot, ~30-day historical realized vol, and a US risk-free proxy are filled when the ticker is found. Strikes and target are recentered near the new spot.
Delayed/free data. Historical realized vol is not implied vol from an options chain. Not investment advice.
New Option Price:
How the short call or put P&L is calculated
A short (naked) option is the mirror of the long: you collect the premium and pay the intrinsic at expiry. Before expiry, the sliders reprice the vanilla with Black-Scholes and the live P&L is premium minus the new price.
Expiry P&L (short call) = Q × [V − max(S − K, 0)]
- V — premium received per option
- Short put expiry P&L = Q × [V − max(K − S, 0)]
- Live P&L = Q × (V − new Black-Scholes price)
Implied vol is solved from V after Calculate, same bisection as the implied-vol page. Default short call (V = 10, S = K = 100, 1%, 365 days) implies 23.97%.
Worked examples
One-lot short call, premium 10, strike 100 — the default chart. These points are the negative of the long-call examples.
Breakeven at 110
Intrinsic of 10 eats the premium. Above 110 a short call loses money, without an upper bound.
- Expiry P&L
- 0
- Breakeven
- K + V = 110
Spot at 130
You owe 30 of intrinsic and only collected 10. A short put’s worst case is if spot goes to zero.
- Expiry P&L
- −20
- Implied vol (from 10)
- 23.97%
Related calculators on this site
A long option flips the sign. Spreads cap the short risk. Implied vol is the solver this page uses after Calculate.
Short call and put FAQ
Upside on the underlier is unlimited, so the short call’s loss is unlimited. You only keep the premium if the option expires out of the money. A short put’s loss is large if spot falls toward zero.
It is the long payoff with the sign flipped: quantity times (premium minus intrinsic). The default short call is profitable below 110 and loses above that.
The premium is inverted after Calculate with the same solver as the implied volatility calculator. Default inputs imply 23.97% on the short call.
You profit if the option cheapens. The AJAX line is quantity times (original premium minus the new Black-Scholes price). If the option’s mark rises, the short is red.
Buy a further out-of-the-money option as a hedge — a call or put spread on the spread calculator — or compare with a long option on the long call/put page.
The implied-vol search needs a premium strictly above intrinsic, using the same vanilla formula as the option calculator. A price at or below intrinsic is rejected.
Disclaimer: the contents of this website are for informational purposes only and do not constitute any investment recommendation. The visitor acts at his own risk.