Short Call (Naked Call)

Core Thesis

A Naked Short Call is a negative-convexity trade with limited income and theoretically unlimited loss. It is generally a professional-only structure used when there is explicit offsetting exposure elsewhere.

Structure

• Short 1 call at strike $K$ for premium $C_0$.
• No long stock hedge and no long-call cap.

Expiration Payoff Mathematics

$$\Pi_T = C_0 - \max(S_T - K, 0)$$

• Max profit: $C_0$.
• Break-even: $K + C_0$.
• Max loss: unlimited as $S_T$ rises.

Risk Profile

• Negative delta, positive theta, short vega, negative gamma.
• Worst profile under rally + volatility expansion (short squeeze regimes).
• Margin can rise rapidly as call moves ITM.

Institutional Controls

• Usually paired against long inventory, dispersion books, or other convex hedges.
• Hard limits on single-name short call exposure.
• Mandatory gap stress scenarios and forced-reduction rules.

Management Framework

• Convert to defined risk early (buy wing, form bear call spread).
• Avoid carrying naked calls through earnings/news catalysts.
• Use stop and time-based exits; avoid "wait for expiration" behavior.

Failure Modes

• Selling small credits repeatedly until one gap erases months/years of gains.
• Ignoring borrow/squeeze dynamics in crowded short names.
• Inadequate liquidity planning under assignment/exercise cycles.

Practical Checklist

• Is there a structural hedge, or is this pure uncapped risk?
• Why is a bear call spread not the better risk-adjusted expression?
• What is the explicit plan if spot gaps above strike pre-open?