MW The narrow foundations of the current rally - one company is responsible for half of S&P 500 earnings revisions

By Steve Goldstein

Micron Technology has accounted for half of the growth in S&P 500 earnings expectations since the beginning of the war.

Talk about a narrow foundation: one company is responsible for half of the increase in S&P 500 earnings expectations since the Iran war started.

That company is Micron Technology $(MU)$, which according to Goldman Sachs calculations has a 51% share of the earnings per share revisions since the Iran war started.

Micron, along with Korean rivals Hynix (KR:000660) and Samsung Electronics (KR:005930), has benefited from a surge in memory-chip demand stemming from artificial-intelligence services.

Three oil giants, Exxon Mobil (XOM), Chevron $(CVX)$ and ConocoPhillips $(COP)$, together have a 29% share of S&P 500 revisions, and microchip giant Broadcom $(AVGO)$ has a 10% share.

The median S&P 500 SPX company, however, has seen no change whatsoever. Still, thanks to the contribution from chips and oil, the current price-to-earnings multiple is actually 5% lower than it was in January.

Strategists led by Ben Snider say the recent rotations in the stock market have generally tracked with earnings revisions. They say the upcoming wave of earnings reports - 94 S&P 500 companies are due to report results this week - will provide a key test for earnings estimates.

The big downside risk is that the war will hit consumer demand and input costs, eating into profit margins, while the upside risk would come from artificial intelligence investment spending and related productivity growth.

The S&P 500 rallied 4.5% last week, the largest one-week percentage gain since the week ending May 16, according to Dow Jones Market Data. The tech-heavy Nasdaq Composite COMP jumped 6.8%.

U.S. stock futures (ES00) (NQ00) however were lower on Monday as Iran reversed its decision to open the Strait of Hormuz.

-Steve Goldstein

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April 20, 2026 04:07 ET (08:07 GMT)

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