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 is the worst month for stocks
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 actually gained ground in five of those 10 years, showing that the so-called September effect does not guarantee a market decline.
John Ternus faces big expectations
The bigger question for Apple shareholders is whether Ternus can maintain the company’s strong performance. He is following two highly successful leaders — Steve Jobs and Tim Cook — and therefore has a very high standard to meet.
Tim Cook’s Apple legacy
Cook’s tenure created enormous value for Apple shareholders. Cook became Apple’s CEO on August 24, 2011, after replacing Jobs. Since then, Apple’s shares have climbed about 2,240% as of August 27, according to USA Today.
Apple’s market value has also exploded during Cook’s time as CEO. The company’s market capitalization increased from about $349 billion in August 2011 to $4.6 trillion today.
Ternus has deep Apple experience
Ternus, however, is not an outsider coming in to run Apple. He has been with the company since 2001, giving him more than two decades of experience inside Apple and a deep understanding of how the business operates.
His long experience at Apple could reduce the risks normally linked to a CEO change. Because Ternus has spent years working inside the company, he is already familiar with Apple’s products, strategy and operations.
Also read: Quote of the day by Tim Cook as he steps down after 15 years as Apple CEO: ‘Use AI for Humanity’
Apple’s hardware business
Ternus has also been part of Apple’s top leadership team for five years. As senior vice president of hardware engineering since 2021, he has played a major role in Apple’s hardware and product development. He has overseen several major device launches during this period. This gives Ternus a strong understanding of the factors that drive Apple’s hardware business and product success, according to USA Today.
iPhone sales remain strong
That experience means Ternus may not need to make major changes when he becomes CEO. The expectation is that Apple could largely continue with the strategy that has already made it one of the world’s most successful companies. The iPhone remains the biggest reason investors continue to watch Apple’s business closely. It is Apple’s key cash-generating product, and sales have continued to show strong growth.
iPhone sales increased 22% year over year during the first three quarters of Apple’s fiscal 2026. That period ended on June 27. Demand for Apple’s iPhone 17 family has also been strong. However, some consumers are still holding off on purchases while waiting for a major artificial intelligence upgrade to Siri.
Apple’s September event
Apple’s upcoming September event could give Ternus an early opportunity to impress investors and consumers. The company is expected to announce new products, including a foldable iPhone.
A major product launch could bring fresh attention to Apple just as Ternus begins his tenure. New devices and announcements could help highlight Apple’s innovation and create renewed interest in the brand.
What Apple investors should watch
Ternus will therefore have an important first test as CEO. He needs to show investors that Apple’s product pipeline remains strong while keeping the company’s existing momentum intact. The broader stock market could make his first month more challenging. September’s historically weak performance means Apple shares could face pressure from overall market volatility even if the company’s own business remains strong.
Investors should not automatically blame Ternus if Apple shares fall in September. A decline could be part of broader market movements rather than a sign that Apple’s new CEO is making mistakes. The S&P 500 has delivered strong returns over the long term despite short-term volatility. Its average annual total return has been about 10%, according to USA Today.
For example, $10,000 invested in the S&P 500 and left untouched for 30 years would grow to about $174,000 at that average return. The example shows why long-term investors generally focus more on years of performance than on a single month.
The stock market does not move upward every year or every month. Investors have to accept periods of losses and volatility if they want to benefit from long-term stock market growth, according to USA Today. That is why Apple shareholders may not need to sell simply because September is historically weak. A single month’s performance is unlikely to make a major difference to an investor who is holding the stock for many years.
The bigger focus for investors should be whether Ternus can keep Apple’s existing business on track. His long history at Apple, experience with hardware and knowledge of the company’s products give him a strong starting point. For now, the expectation is largely “business as usual” at Apple. Ternus does not necessarily need to reinvent the company; his challenge is to protect what is already working while guiding Apple through its next phase of growth.
For long-term investors, September’s market weakness may be more noise than a reason to panic. The key question will be whether Apple continues to grow its products, sales and technology business over the years ahead rather than how the stock performs in one difficult month.
