Amazon’s Stock Performance

On October 31, 2025, Amazon, the world’s largest online retailer, saw its shares reach a record high. This was primarily due to the success of its cloud computing business, Amazon Web Services, which contributed to the company’s better-than-expected quarterly results. Amazon’s stock jumped almost 10% to a record closing.

Amazon’s Cloud Computing Success

Amazon’s robust quarterly results can be attributed to the growth of its Amazon Web Services business. CEO Andy Jassy emphasized the company’s plan to expand its Artificial Intelligence (AI) capabilities as it sees increasing demand for AI infrastructure. The better-than-expected earnings for the third quarter are detailed here.

DexCom’s Stock Performance

Despite Amazon’s success, not all companies experienced such positive results. Shares of DexCom, the maker of glucose monitoring devices, plunged as the company provided a cautious revenue forecast, resulting in the stock’s nearly 15% tumble. This marked the steepest daily decline in the S&P 500 on October 31, 2025.

Concerns Over DexCom’s Revenue Growth

DexCom’s management team expressed concerns about potential shortfalls in the company’s 2026 revenue growth, despite topping third-quarter sales and profit estimates. The company has also been dealing with quality issues related to its flagship G7 sensor, but executives assured that the problem had been resolved earlier in the year.

Overview of the Stock Market on October 31, 2025

As the month concluded, most major U.S. equities indexes finished higher. The Dow ticked up 0.1%, the S&P 500 advanced 0.3%, and the Nasdaq climbed 0.6%. All three indexes posted gains for the week and month. More information about the market’s activity on that day can be found here.