Understand why covered and naked calls consume buying power differently—and why margin is not a measure of maximum loss.
Covered-call collateral
A covered call is generally secured by 100 shares per standard contract. The shares remain exposed to market loss and may be restricted from sale while the call is open unless the option is closed simultaneously.
Some accounts display little additional option margin because the delivery obligation is backed by stock.
Naked-call requirements
A naked call requires advanced approval and formula-based margin. Requirements can depend on stock price, option value, out-of-the-money amount and broker house rules.
As the stock rises or volatility expands, required margin can increase at the same time the position loses money.
Buying-power and liquidation risk
Insufficient equity can trigger a margin call or forced liquidation. A broker may act without waiting for the trader’s preferred exit.
Keep a buffer above the displayed requirement and stress-test sharp price gaps rather than assuming continuous trading.
Position sizing
Size short calls by worst-case portfolio impact, not by premium target. Consider correlated positions that could move together during a rally or volatility shock.
Defined-risk call spreads may be an alternative when a capped loss is required, though they introduce their own trade-offs.
A practical example
Assume 100 shares, one short call and a clearly defined strike and expiration. Record the stock price, premium received, maximum called-away value and downside breakeven before placing the order. Then model outcomes below the strike, at the strike and well above it.
Option contracts involve assignment and expiration rules. Confirm contract specifications and broker requirements for the exact product being traded.
Frequently asked questions
Is margin the maximum loss?
No. Naked-call loss can exceed the initial margin substantially.
Why can margin increase?
Because price, volatility and broker requirements can change.
Does owning shares cover the call?
Normally 100 eligible shares cover one standard equity call, subject to broker rules.
Continue the Selling Call Options cluster
Explore related guides: What Is Selling a Call Option and How Does It Work? Covered Call vs Naked Call: Risk and Reward Compared How to Sell a Covered Call: Step-by-Step Guide. For a structured sequence, use the free Level 2 – Selling Call Option Strategy course.
Options involve risk and are not suitable for every investor. This material is educational and is not investment, tax or legal advice. Contract terms and broker requirements can vary.