Key Takeaways
- • The Nasdaq Composite fell approximately 5% in October 2026 while the S&P 500 declined about 1%, and the S&P 500 Equal Weight Index gained approximately 5%, according to Data Insights, a division of Hazeltree.
- • Amazon, Apple, Nvidia, and Meta recorded increases in short fund participation among the Magnificent Seven, with Microsoft and Alphabet also registering gains; Tesla was the only Magnificent Seven stock to see a decline in short participation.
- • CoreWeave's default insurance costs widened and its 2032 bonds yielded close to 15%, a level Data Insights says is approaching distressed-debt territory.
- • Advanced Micro Devices shifted from a long-biased to a short-biased position in October, and Entegris became the most crowded semiconductor short.
- • Kimberly-Clark recorded the largest rise in North American large-cap short crowding, per the Data Insights Crowding Report October 2026, based on roughly 16,000 securities across more than 700 global funds.
Summary
Markets experienced a sharp rotation in October 2026, with investors moving away from some of the largest technology stocks amid concerns around AI infrastructure financing and credit conditions, according to Data Insights, a division of Hazeltree, the institutional hedge fund market intelligence platform. The Nasdaq Composite fell approximately 5% over the month, while the S&P 500 declined approximately 1%. The S&P 500 Equal Weight Index, which gives smaller weight to the largest names, gained approximately 5%, highlighting stronger performance outside the largest technology companies.
Within the Magnificent Seven, short fund participation rose in Amazon, Apple, Nvidia, and Meta, and also increased in Microsoft and Alphabet. Tesla was the only member of the group to see a decline in short participation. Data Insights also reported that overall semiconductor sentiment turned less bullish during the month. AMD stood out after shifting from a long-biased to a short-biased position, and Entegris became the most crowded semiconductor short, followed by ON Semiconductor and AMD.
Tim Smith, managing director at Data Insights, Hazeltree, said October brought a sharp rotation out of some of the largest technology stocks as major indices fell, while non-technology sectors performed well. He added that AI infrastructure builders experienced credit strain, most notably CoreWeave, whose default insurance costs widened and whose 2032 bonds yielded close to 15%, approaching levels typically associated with distressed debt.
The Data Insights Crowding Report October 2026, formerly known as the Hazeltree Crowding Report, evaluates the 10 most crowded regional short positions across large, mid, and small-cap categories in the Americas, EMEA, and APAC. In North America, Kimberly-Clark recorded the largest rise in large-cap short crowding, while Dick's Sporting Goods, Tenable, Hims & Hers, Freshpet, Wynn Resorts, and Vaxcyte led mid-caps, and The Greenbrier Companies and Ziff Davis topped small-caps. In EMEA, Kering, BT Group, and Capgemini led large-caps, with Alstom and JD Sports among mid-caps. In APAC, Ibiden, Toyota, and Oriental Land Co recorded notable large-cap increases, while Harmonic Drive Systems and J Front Retailing led mid-caps and DroneShield, Minerals 260, Furuya Metal, and Infomart featured among small-cap short positions.
The analysis draws on data from approximately 16,000 securities on Data Insights' proprietary securities finance platform, representing more than 700 global funds.
Within the Magnificent Seven, short fund participation rose in Amazon, Apple, Nvidia, and Meta, and also increased in Microsoft and Alphabet. Tesla was the only member of the group to see a decline in short participation. Data Insights also reported that overall semiconductor sentiment turned less bullish during the month. AMD stood out after shifting from a long-biased to a short-biased position, and Entegris became the most crowded semiconductor short, followed by ON Semiconductor and AMD.
Tim Smith, managing director at Data Insights, Hazeltree, said October brought a sharp rotation out of some of the largest technology stocks as major indices fell, while non-technology sectors performed well. He added that AI infrastructure builders experienced credit strain, most notably CoreWeave, whose default insurance costs widened and whose 2032 bonds yielded close to 15%, approaching levels typically associated with distressed debt.
The Data Insights Crowding Report October 2026, formerly known as the Hazeltree Crowding Report, evaluates the 10 most crowded regional short positions across large, mid, and small-cap categories in the Americas, EMEA, and APAC. In North America, Kimberly-Clark recorded the largest rise in large-cap short crowding, while Dick's Sporting Goods, Tenable, Hims & Hers, Freshpet, Wynn Resorts, and Vaxcyte led mid-caps, and The Greenbrier Companies and Ziff Davis topped small-caps. In EMEA, Kering, BT Group, and Capgemini led large-caps, with Alstom and JD Sports among mid-caps. In APAC, Ibiden, Toyota, and Oriental Land Co recorded notable large-cap increases, while Harmonic Drive Systems and J Front Retailing led mid-caps and DroneShield, Minerals 260, Furuya Metal, and Infomart featured among small-cap short positions.
The analysis draws on data from approximately 16,000 securities on Data Insights' proprietary securities finance platform, representing more than 700 global funds.
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