India, Sept. 1 -- John Ternus is taking over as Apple CEO on September 1, replacing Tim Cook at the top of the world's most valuable technology companies. Ternus will become CEO after serving as Apple's senior vice president of hardware engineering since 2021.

The timing of Ternus' promotion is important for Apple investors. He is taking charge just as September begins, a month that has historically been the weakest month of the year for the broader US stock market, according to USA Today.

September has earned a reputation as the "worst month" for stocks. Between 2016 and 2025, the S&P 500 recorded an average return of -1.3% during September.

However, a weak historical average does not mean stocks will fall every September. The S&P 500...