How assignment works

Assignment is one of the most misunderstood mechanics in options trading, and one of the most important to understand before you sell your first option. When you sell an option and the buyer decides to exercise, you're assigned. That assignment comes with real obligations: you must buy or deliver shares at the strike price, regardless of where the stock is trading.

The mechanics of assignment

When you sell (write) an options contract, you take on an obligation:

• Short call: If assigned, you must sell 100 shares at the strike price
• Short put: If assigned, you must buy 100 shares at the strike price

The buyer of the option has the right to exercise. If they do, your broker receives an assignment notice, and the transaction is processed, typically overnight.

When does assignment happen?

At expiration (most common): Standard assignment occurs when an ITM option expires. Most brokers automatically exercise long ITM options at expiration if they're in the money by $0.01 or more. As the short option seller, you receive the corresponding assignment.

Rule of thumb: If your short option is ITM at expiration, assume you will be assigned.

Early assignment (before expiration): American-style equity options can be exercised by the long holder at any time before expiration. Early assignment is less common but does occur in specific situations:

• Dividends: If you're short a call on a stock with an upcoming ex-dividend date, and the call has little or no extrinsic value remaining, the long holder may exercise early to capture the dividend. This is the most common early assignment trigger.
• Deep ITM puts: If a short put is deep ITM with nearly zero extrinsic value, early exercise may make sense for the long holder.

What happens after assignment

Assigned on a short call: You're required to sell 100 shares at the strike price. If you own the shares (covered call), they're delivered. If you don't (naked call), your broker will either:

• Buy shares in the open market and deliver them (creating a potential loss)
• Issue a margin call to cover the position

This is why selling naked calls is extremely high risk, assignment on a rising stock can be very costly.

Assigned on a short put: You're required to buy 100 shares at the strike price. The cash is debited from your account and 100 shares are credited. This is exactly what the cash-secured put strategy is designed for, you hold cash equal to the purchase obligation, and if assigned, you simply own the stock at your chosen price.

Assignment is not always bad

For income strategies, assignment is part of the plan:

Cash-secured put assignment: You wanted to own the stock at a lower price. Assignment means you bought it at the strike, with your effective cost basis reduced by the premium collected. No problem.

Covered call assignment: Your shares were called away at the strike price. You keep the premium and the gain up to the strike. The trade worked exactly as intended.

The wheel strategy: Assignment on a cash-secured put leads directly to the next phase, selling covered calls against the shares you just received. Assignment is a feature, not a bug.

How to avoid unwanted assignment

Close before expiration: If your short option is ITM and you don't want to be assigned, close the position before expiration. Buy back the short option before Friday's close on expiration week.

Roll the position: Buy back the short option and sell a new one at a later expiration or better strike, often for a net credit. This extends the trade and avoids assignment.

Watch dividend dates: If you're short a call on a dividend-paying stock, check the ex-dividend date. If the call is deep ITM and has little extrinsic value, early assignment is possible in the days before the ex-dividend date.

The assignment timeline

1. Exercise notice received, long holder notifies their broker of exercise intent (before 5:30pm EST on business days, typically)
2. OCC processes, the Options Clearing Corporation randomly assigns the exercise notice to a short holder at a broker with open positions
3. Your broker notifies you, assignment notice appears in your account, usually overnight
4. Transaction settles, shares are delivered or purchased, typically on the next business day (T+1)

Related terms: Exercise, cash-secured put, covered call, expiration date, pin risk, the wheel, early assignment

Try it on Stryke: Monitor your short positions approaching expiration in the Portfolio tracker.

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