**Apple holds a strong lead as the implied frontrunner for second-largest company by market capitalization at the end of September 2026, with an 84.5% market-implied probability.** NVIDIA currently leads overall at roughly $5.1 trillion, while Apple sits comfortably in second at approximately $4.8–4.9 trillion, ahead of Alphabet (around $4.1–4.2 trillion) and Microsoft (near $3.7 trillion). Recent trading data through mid-September shows Apple maintaining this position amid ongoing AI-driven gains for chipmakers and steady performance in consumer electronics and services. The roughly $600–700 billion gap to Alphabet has proven resilient, and with only two weeks remaining, extreme short-term volatility or major announcements would be required to reorder the top ranks. NVIDIA’s modest 12.7% probability likely reflects tail-risk scenarios where its valuation slips relative to Apple, while very low odds for Microsoft, Amazon, Tesla, and others align with their larger distance from the second spot. Traders appear to view the current hierarchy as stable barring unforeseen catalysts.