Assuming that equities are expected to earn more than the risk free rate (ie, have a positive equity risk premium), this lower delta can mean more money is lost by having a less equity-sensitive portfolio than is gained by selling expensive volatility. On average, call overwriting appears to be a successful strategy, and its success has meant that it is one of the most popular uses of trading options.
OVERWRITING WITH NEAR-DATED OPTIONS IS BEST
Near-dated options have the highest theta, so an investor earns the greatest carry from call overwriting with short-dated options. It is possible to overwrite with 12 one-month options in a year, as opposed to four three-month options or one 12-month option.
While overwriting with the shortest maturity possible has the highest returns on average, the strategy does have potentially higher risk. If a market rises one month, then retreats back to its original value by the end of the quarter, a one-month call overwriting strategy will have suffered a loss on the first call sold but a three-month overwriting strategy will not have had a call expire ITM.
However, overwriting with far-dated expiries is more likely to eliminate the equity risk premium the investor is trying to earn (as any outperformance above a certain level will be called away).
- Figure 10. Call Overwriting SX5E with One-Month Calls of Different Strikes: