Early Assignment Risk and the Ratio Call Spread: A Trader's Guide

Introduction

For the writer of options, particularly uncovered or naked options, the specter of early assignment is a constant and often misunderstood risk. The ratio call spread, with its two short call options, is no exception. While the probability of early assignment may be low, its consequences can be significant, disrupting the intended structure of the trade and potentially leading to unintended consequences. This article will provide a comprehensive guide to understanding and managing early assignment risk in the context of the ratio call spread, equipping the professional trader with the knowledge to navigate this potential pitfall.

What is Early Assignment?

Early assignment occurs when the owner of an American-style option exercises their right to buy or sell the underlying asset before the option's expiration date. For the writer of a call option, this means being obligated to sell the underlying stock at the strike price. In a ratio call spread, the two short call options are subject to this risk.

Why Does Early Assignment Occur?

The primary reason for the early exercise of a call option is to capture a dividend payment. If a stock is about to go ex-dividend, an in-the-money call option holder may choose to exercise the option to buy the stock and receive the dividend. The decision to exercise early is a rational one if the dividend payment is greater than the remaining time value of the option.

Condition for Early Exercise of a Call Option:

Dividend > Time Value of the Call Option

Another reason for early exercise, although less common, is a desire to own the underlying stock. This is more likely to occur with deep in-the-money calls that have very little time value remaining.

The Impact of Early Assignment on a Ratio Call Spread

If one of the short call options in a ratio call spread is assigned early, the trader will be short 100 shares of the underlying stock for each contract assigned. This will have a significant impact on the risk profile of the position.

Let's consider our 1x2 ratio call spread example:

• Long 1 XYZ 100 Call
• Short 2 XYZ 105 Calls

If one of the 105 calls is assigned, the new position will be:

• Long 1 XYZ 100 Call
• Short 1 XYZ 105 Call
• Short 100 shares of XYZ stock

This new position is a combination of a bull call spread and a short stock position. The delta of the position will become significantly more negative, and the risk profile will be dramatically altered.

Managing Early Assignment Risk

While it is impossible to eliminate the risk of early assignment completely, there are several steps that the professional trader can take to manage it:

• Avoid Trading Around Dividends: The most effective way to avoid early assignment is to avoid holding short call positions in stocks that are about to go ex-dividend. If a trader is in a ratio call spread and the underlying stock announces a dividend, they should consider closing the position before the ex-dividend date.

• Monitor the Time Value of the Short Calls: The trader should keep a close eye on the time value of the short call options. If the time value decays to a very low level, the risk of early assignment increases. In this situation, the trader may want to consider rolling the position to a later expiration date to increase the time value.

• Trade European-Style Options: European-style options can only be exercised at expiration. By trading options on indexes such as the S&P 500 (SPX), the trader can eliminate the risk of early assignment altogether.

What to Do if You Are Assigned

If you are assigned on one of your short calls, you have a few options:

1. Exercise your long call to cover the short stock position: This is the most straightforward solution. You would exercise your long 100 call to buy 100 shares of XYZ, which would offset your short stock position. This would leave you with a single short 105 call.

2. Buy the stock in the open market to cover the short position: If you do not want to exercise your long call, you can buy the stock in the open market to cover your short position. This would also leave you with a single short 105 call.

3. Do nothing and hold the short stock position: This is the riskiest option, as you would be exposed to unlimited losses if the stock price continues to rise. This is generally not recommended unless you have a strong bearish bias on the stock.

Conclusion

Early assignment is a real and present danger for the writer of options, and the ratio call spread is no exception. The professional trader must have a thorough understanding of the causes of early assignment and must have a plan in place to manage this risk. By avoiding trades around dividends, monitoring the time value of the short calls, and knowing what to do in the event of an assignment, the trader can navigate this potential pitfall and protect their capital.