The Dow Jones and S&amp;P 500 have experienced a historic divergence.
On Thursday, the Dow fell by 1.2%, while the S&amp;P 500 rose by as much as 0.6%. This situation is extremely rare—media compilation data shows that the Dow has fallen by 1% or more while the S&amp;P 500 has risen by at least 0.5% only once since 1954.
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The &#34;culprit&#34; behind this historic divergence is the plummeting stock price of UnitedHealth.
As the highest-weighted component in the Dow Jones index, UnitedHealth's stock price fell by 18% after releasing disappointing earnings (the first time in over a decade) and lowering its full-year earnings forecast, marking the largest single-day drop since 1999.
As of Wednesday's close, the Dow has fallen by 6.8% this year, outperforming the S&amp;P's 10% decline and the Nasdaq 100's 13% drop.
<h2>Key Differences in Weighting Calculation Methods</h2>
This divergence reveals the fundamental differences in the construction methods of the two indices.
The Dow uses a price-weighted method, meaning that price changes in high-priced stocks have a greater impact on the index than those in low-priced stocks; while the S&amp;P is calculated based on market capitalization, making it less sensitive to unusual fluctuations in a single stock.
Michael O'Rourke, Chief Market Strategist at JonesTrading, stated:
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“Although major stock indices typically move in sync, today's movement is a rare large fluctuation in a high-priced stock within the Dow, leading to market divergence.”
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In the weight ranking of the Dow, UnitedHealth is followed by Goldman Sachs, Microsoft, and Home Depot. In contrast, the top positions in the S&amp;P 500 are occupied by tech giants such as Apple, Microsoft, Nvidia, Amazon, and Meta

Nvidia will release its first quarter report for fiscal year 2026 ending April 27, 2025. 

According to analysts surveyed by FactSet, Nvidia's first-quarter revenue is expected to increase 66% year-on-year to $43.3 billion; adjusted earnings per share will increase 44% year-on-year to $0.88. The growth rate of revenue and profits has slowed significantly compared with the same period last year. In the same period last year, Nvidia's revenue increased by 262% year-on-year, and its adjusted earnings per share increased by 461% year-on-year.

Nvidia will release its first quarter report for fiscal year 2026 ending April 27, 2025. According to analysts surveyed by FactSet, Nvidia's first-quarter revenue is expected to increase 66% year-on-year to $43.3 billion; adjusted earnings per share will increase 44% year-on-year to $0.88. The growth rate of revenue and profits has slowed significantly compared with the same period last year. In the same period last year, Nvidia's revenue increased by 262% year-on-year, and its adjusted earnings per share increased by 461% year-on-year.

NVIDIA Financial Results for Q4 Fiscal 2025

The Dow Jones Industrial Average uses a price-weighted method, which means that price changes in high-priced stocks have a greater impact on the index than those in low-priced stocks. The largest weighted stock, Unitedhealth, plummeted 18% overnight, dragging the Dow down by 1.2%, while the S&P 500 index rose by as much as 0.6% at the same time. Media compilation data shows that the Dow has fallen by 1% or more while the S&P has risen by at least 0.5% only once since 1954

- On Thursday, the Dow Jones Industrial Average fell by 1.2%, while the S&P 500 rose by up to 0.6%, marking a rare divergence not seen since 1954.  
- This unusual occurrence was primarily driven by a significant 18% drop in UnitedHealth's stock price, following disappointing earnings and lowered forecasts, which is the largest single-day decline since 1999.  
- The divergence highlights the fundamental differences in index construction, with the Dow being price-weighted and the S&P 500 being market-cap weighted, affecting their sensitivity to individual stock fluctuations.

Wallstreetcn

Unitedhealth

S&P 500

Apple

Weighted stocks plummet, the Dow Jones, the "most resilient" in the U.S. stock market, suffers a sharp decline against the trend