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August 21, 2026 · week in review

Chipmakers and Industrials Slide While Health Care Rallies to Cushion the Week

The S&P 500 fell 1.43% as Nvidia, Broadcom and AMD dragged tech lower, even as Eli Lilly, Merck and Amgen powered a health care rebound.

The S&P 500 closed the week at 7,674.37, down 111.39 points, or 1.43%, from August 14 to August 21. Breadth was mixed rather than one-sided: 202 of the index's 503 members finished higher, and the concentration reading of 48% shows the loss was not the work of a handful of names alone, even though the largest movers pulled hard in one direction. The equal-weight version of the index fell 0.56%, close to the cap-weighted decline, which tells you this was a broad drawdown rather than a mega-cap-only story. Nvidia was the single biggest drag, subtracting 30.21 points as shares fell 4.64%. Broadcom, Meta Platforms, Microsoft and AMD rounded out the top five detractors, all posting losses between 2.27% and 8%. On the other side, Eli Lilly added 6.85 points on a 6.32% gain, and Tesla, Apple, Merck and AbbVie each contributed smaller positive amounts, with Merck's 12.29% jump the standout percentage move of the week.

The S&P 500 through the session S&P 500 attribution map, cell size = points contributed

The Dow

The DJIA closed at 53,277.00, down 455.41 points, or 0.85%, a smaller percentage decline than the S&P despite far weaker breadth: only 12 of its 30 members rose. Concentration ran high at 84%, and the mode is flagged as narrow, meaning a small group of stocks did nearly all the work. Caterpillar led the damage, subtracting 170.88 points on a 3.36% drop, followed by Honeywell and Boeing, each down more than 7% and each costing the index over 100 points. Sherwin-Williams and Microsoft filled out the top five detractors. The Dow's story diverges from the S&P's in its healthcare offset: Amgen added 143.36 points on a 5.81% gain and Merck added 99.26 points on its 12.29% surge, together doing more to cushion the Dow than health care did for the broader index, where Lilly was the only top-five contributor from the sector.

The Dow through the session Dow attribution map, cell size = points contributed

The Nasdaq 100

The Nasdaq 100 fell hardest of the three, closing at 29,308.86, down 737.28 points, or 2.45%. Breadth was the weakest of the week: just 44 of 102 members advanced, concentration sat at 72%, and the payload labels the week's pattern as divergence. Nvidia alone cost the index 238.20 points, Broadcom another 185.24, and Space Exploration Technologies, AMD and Intel filled out the rest of the top five, with Intel down 12.13%. That chip-heavy selling is the clearest split from the S&P and Dow stories this week: the same names that were minor drags on the broader index were the dominant force here. Apple was the largest offset, adding 177.24 points on a modest 1.12% gain, with Tesla, Amazon, Marvell and Netflix also finishing in positive territory.

The Nasdaq 100 through the session Nasdaq 100 attribution map, cell size = points contributed

The sectors

Across the eleven sectors, the split was sharp: three groups gained while eight fell. Health Care and Energy led the advancers, while Technology, Utilities and Industrials posted the steepest declines of the week.

The 11 sectors by move, top contributor named

Health Care was the strongest sector, up 4.33% and adding 7.25 points, with Eli Lilly as its top driver, contributing 1.66 points on a 6.32% gain.

Health Care: what moved it

Technology was the weakest sector, down 3.51% and subtracting 6.66 points, narrowly worse than Utilities' 3.5% decline. Nvidia was the sector's top driver, costing 1.36 points on its 4.64% drop.

Technology: what moved it

The payload does not include a percentile ranking for this week's moves against the past year for any of the three indices, so no claim about how large or small this week ranks historically can be made here.

The numbers

From Babylon Burns

WMTMT is brought to you by the founders of Babylon Burns. If you want to stay ahead of the markets, read their recent piece on healthcare while everyone else runs: Left for dead: buying healthcare while everyone else runs.

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Compiled by the WMTMT attribution engine from the session's official data · built by the founders of Babylon Burns