Stock Markets January 27, 2026

Stocks Swing Widely as Healthcare Names Lead Declines and Tech, Semiconductors Post Gains

UnitedHealth, Humana and CVS tumble after Medicare Advantage rate proposal; semiconductors and select cloud and data center plays rise

By Leila Farooq UNH ORCL MU LRCX
Stocks Swing Widely as Healthcare Names Lead Declines and Tech, Semiconductors Post Gains
UNH ORCL MU LRCX

Trading on Tuesday produced sharp moves across market-cap bands, with large healthcare insurers among the weakest names after policy news and a mix of gains in semiconductors, cloud and data center-related stocks. Mega-cap losses included UnitedHealth, while Humana and CVS were large-cap decliners. A range of mid- and small-cap companies also recorded outsized moves tied to earnings, guidance and contract announcements.

Key Points

  • Healthcare insurers fell sharply following reports of a proposed flat-rate approach to Medicare Advantage, affecting multiple market-cap tiers.
  • Semiconductor and data center-related stocks led gains, producing several double-digit percentage increases in mega- and mid-cap groups.
  • Mid- and small-cap volatility was driven by earnings misses, revenue guidance shortfalls and significant contract awards.

U.S. markets saw sizable intraday swings on Tuesday, with movements driven by a combination of policy headlines, earnings developments, guidance revisions and corporate deal announcements. Healthcare insurers led the declines among the largest names, while several technology and semiconductor companies posted notable gains.


Summary

Policy-related reporting that the Trump administration has proposed flat rates for Medicare Advantage - a development attributed to CMS and the White House in media reports - corresponded with sharp drops in shares of several health insurers. Elsewhere, strength in the semiconductor group and in companies tied to cloud and data center activity produced multiple double-digit percentage increases across market-cap categories. Mid- and small-cap names were volatile as earnings misses, revenue guidance shortfalls and new contract awards moved share prices sharply in both directions.


Top movers by market-cap category

Mega-Cap Movers ($200 billion USD or higher):

  • United Health Group (UNH); Trump Administration Proposes Flat Rates for Medicare Advantage, CMS and White House Say -- WSJ: -17.64%
  • Oracle Corp (ORCL): -3.83%
  • Micron Tech (MU): +5.0%
  • Lam Research Corp (LRCX): +6.25%
  • Applied Matls Inc (AMAT): +4.87%
  • Intel Corp (INTC): +3.36%
  • Alibaba-exch (BABA): +1.88%
  • Apple Computer Inc (AAPL): +1.79%

Large-Cap Stock Movers ($10-$200 billion USD):

  • Humana Inc (HUM); Trump Administration Proposes Flat Rates for Medicare Advantage, CMS and White House Say -- WSJ: -18.91%
  • Roper Industries (ROP): -13.99%
  • Centene (CNC): -12.14%
  • Wellpoint Inc (ELV): -11.04%
  • Cvs Corp (CVS); Trump Administration Proposes Flat Rates for Medicare Advantage, CMS and White House Say -- WSJ: -10.9%
  • Corning Inc (GLW); Corning and Meta sign up to $6 billion deal for U.S. data centers: +16.65%
  • Cloudflare Inc (NET): +13.98%
  • Amark Preci (GOLD): +12.54%
  • HCA Holdings Inc (HCA); HCA Healthcare beats Q4 earnings, stock falls on revenue miss: +9.54%
  • Regencell Bioscience Holdings (RGC): +9.21%

Mid-Cap Stock Movers ($2-$10 billion USD):

  • Commvault System (CVLT): -33.79%
  • Agilysys (AGYS); Agilysys shares tumble after Q3 earnings miss: -21.35%
  • Sanmina-SCI Corp (SANM); Sanmina shares tumble as revenue guidance falls short of expectations: -16.73%
  • Alignment Healthcare LLC (ALHC): -14.41%
  • Redwire (RDW); Redwire secures position on $151b MDA SHIELD contract: +29.85%
  • Kingsoft Cloud Holdings Ltd (KC): +10.91%
  • TECO Energy Inc-Exch (TE): +10.57%
  • Popular Inc (BPOP); Popular tops Q4 EPS by 50c, shares edge higher: +5.65%
  • Planet Labs PBC (PL): +8.29%
  • NantKwest (IBRX): -5.34%

Small-Cap Stock Movers ($300 million - $2 billion USD):

  • NovaBay Pharmaceuticals Inc (NBY): -34.13%
  • Apollo Medical (ASTH): -19.18%
  • World Acceptance (WRLD); World Acceptance misses Q3 EPS, shares fall on higher loan provisions: -17.96%
  • agilon health (AGL): -10.49%
  • New Fortress Energy LLC (NFE): -9.3%
  • Junee (SUPX): +33.56%
  • Richtech Robotics (RR): +22.08%
  • HUYA Inc (HUYA): +20.03%
  • Hyperliquid Strategies (PURR): +12.3%
  • MUU (MUU): +9.41%

Interpretation

The most consequential moves on the day clustered in healthcare and technology-related names. Reporting that the administration proposed flat Medicare Advantage rates corresponded with sharp declines at several insurer stocks across market-cap tiers. Conversely, companies tied to semiconductors, data centers and cloud services showed strength, including double-digit percentage gains for several mid-cap names linked to contracts or sector momentum. Mid- and small-cap volatility was pronounced and often traceable to company-specific earnings or guidance announcements.


Key points

  • Healthcare insurers were among the largest decliners after reports of a proposed flat-rate approach to Medicare Advantage - this affected mega- and large-cap names.
  • Semiconductor and data center-linked stocks produced some of the day's largest percentage gains, impacting technology and materials sectors.
  • Mid- and small-cap performance was driven by a mix of earnings misses, revenue guidance shortfalls and contract awards, contributing to high single-day volatility in those segments.

Risks and uncertainties

  • Policy developments related to Medicare Advantage rates create uncertainty for health insurers and could pressure share prices in the healthcare sector.
  • Earnings misses and disappointing revenue guidance at individual companies can rapidly erode investor confidence, particularly among mid- and small-cap issuers.
  • Contract announcements and sector-specific momentum can produce outsized gains that may be reversed if follow-through or broader market conditions change.

Market participants should note the pronounced cross-sector divergence evident in the day's trading, with policy news affecting healthcare while tech and semiconductor names advanced on industry-specific drivers.

Risks

  • Policy proposals on Medicare Advantage rates introduce uncertainty for the healthcare sector and associated equities.
  • Company-level earnings misses or weak guidance can trigger steep declines, especially among mid- and small-cap stocks.
  • Sector-specific rallies tied to contracts or media reports may reverse if subsequent information fails to support continued momentum.

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