S&P 500 Gains and Losses Today: Amazon Stock Surges as Cloud Business Boosts Earnings; DexCom Drops

Amazon shares surged to a record high following better-than-expected third-quarter earnings, primarily driven by robust growth in Amazon Web Services and plans to expand AI capacity. Conversely, DexCom shares plummeted nearly 15% due to a cautious 2026 revenue growth outlook and concerns over its G7 sensor, despite beating current quarter estimates. Other notable movers included First Solar, which gained over 14% on strong revenue and new manufacturing initiatives, and Coinbase, which rose nearly 5% on strong trading volumes and positive regulatory sentiment, contributing to a broadly positive day for major U.S. equity indexes.

Analysis

Amazon (AMZN) shares surged nearly 10% to a record high, driven by better-than-expected third-quarter earnings and robust growth in its Amazon Web Services (AWS) segment. CEO Andy Jassy's emphasis on boosting AI capacity signals strategic alignment with increasing demand for AI infrastructure, positioning the company for continued expansion.

In contrast, DexCom (DXCM) experienced a significant nearly 15% decline, marking the steepest daily drop in the S&P 500, despite exceeding Q3 sales and profit estimates. The primary catalyst was management's cautious 2026 revenue growth forecast and ongoing concerns regarding the G7 sensor's quality, which the company claims to have addressed earlier this year.

First Solar (FSLR) gained over 14% on strong revenue from U.S. solar project demand and plans for a new 3.7 GW manufacturing facility, while Coinbase (COIN) rose nearly 5% due to increased trading volumes and optimism around digital asset regulation. Conversely, Erie Indemnity (ERIE) slid 5.5% as underwriting losses from severe weather impacted revenue, highlighting sector-specific vulnerabilities.

The broader market finished higher, with the S&P 500 advancing 0.3%, supported by a Federal Reserve rate cut and a U.S.-China trade truce, indicating a moderately positive sentiment despite individual company-specific challenges.

Key Decisions for Investors

• Investors should closely track Amazon's AWS segment growth and AI investment progress, as these are critical for future revenue expansion and market leadership.
• Exercise caution with DexCom, focusing on management's 2026 revenue guidance and the effective resolution of G7 sensor quality issues, which present significant near-term headwinds despite current quarter beats.
• Consider First Solar's strategic capacity expansion and Coinbase's growth in trading volumes and new initiatives within the context of evolving regulatory environments for potential long-term opportunities.
• Maintain awareness of sector-specific risks, such as weather-related underwriting losses impacting insurers like Erie Indemnity, and broader market sentiment influenced by macroeconomic factors.