For holdings in the portfolio, does implementing Covered Calls over the long term actually enhance returns?

Opinions on this question vary. I conducted a small backtest during the holiday period, covering the date range: 2023-01-03 to 2026-10-02.

Days to Expiration (DTE): 2 weeks.

Strike price set at 9% OTM.

Using the US Magnificent Seven tech stocks as an example, the backtest results show that only NVDA and AMZN slightly outperformed long-only stock holding; for the other stocks, buying and holding without writing covered calls yielded better returns.

This result may surprise many. However, it's understandable that people have the illusion that selling options is easy money, because selling out-of-the-money options, especially those 9% OTM, are inherently high-probability strategies.

Unfortunately, historical data suggests that if the underlying asset is one of the Magnificent Seven tech stocks that have surged significantly in recent years, Covered Calls tend to be high-probability but negative expected value strategies.

$Apple(AAPL.US), $Microsoft(MSFT.US), $Alphabet - C(GOOG.US), $Amazon(AMZN.US), $Meta Platforms(META.US), $NVIDIA(NVDA.US), $Tesla(TSLA.US)