The Morningstar UK Large-Mid Cap Index rose 1.76% in the third quarter amid a rally in the energy sector. The index tracks the performance of the top 90% of the UK investable universe by market cap, and each quarter, we screen it for the best- and worst-performing companies. Data in this article is sourced from Morningstar Direct.
The Best-Performing Stocks of Q3 2026
The Worst-Performing Stocks of Q3 2026
Metrics for the Best-Performing Stocks
Ithaca Energy ITH
- Sector: Energy
- Industry: Oil & Gas E&P
- Economic Moat: Not Rated
Ithaca Energy surged 31.82% in the third quarter, leaving the stock up 55.53% for the past year. The company’s stock has a quantitative Morningstar Rating of 3 stars.
Lion Finance Group BGEO
- Sector: Financial Services
- Industry: Banks - Regional
- Economic Moat: Not Rated
Lion Finance Group leapt 27.65% in the third quarter, leaving shares up 93.52% for the past year. Lion Finance Group has a quantitative Morningstar Rating of 3 stars.
Computacenter CCC
- Sector: Technology
- Industry: Information Technology Services
- Economic Moat: Not Rated
Computacenter climbed 27.12% in the third quarter, leaving the stock up 104.58% for the past year. The company’s stock has a quantitative Morningstar Rating of 2 stars.
Harbour Energy HBR
- Sector: Energy
- Industry: Oil & Gas E&P
- Economic Moat: Not Rated
Harbour Energy leapt 25.30% in the third quarter, leaving shares up 32.71% for the past year. Harbour Energy has a quantitative Morningstar Rating of 5 stars.
Persimmon PSN
- Sector: Consumer Cyclical
- Industry: Residential Construction
- Economic Moat: None
Persimmon climbed 25.24% in the third quarter, leaving the stock up 19.76% for the past year. The company’s stock has a Morningstar Rating of 3 stars and trades near the fair value estimate of £12.80.
Metrics for the Worst-Performing Stocks
Rentokil Initial RTO
- Sector: Industrials
- Industry: Specialty Business Services
- Economic Moat: Narrow
Rentokil Initial slid 29.68% in the third quarter, leaving the stock down 19.19% for the past year. Shares were 41.38% below their last high on April 15, 2026. The company’s stock has a Morningstar Rating of 4 stars, trading at a 42% discount to its fair value estimate of £5.10.
IG Group Holdings IGG
- Sector: Financial Services
- Industry: Capital Markets
- Economic Moat: Not Rated
IG Group Holdings dropped 26.33% in the third quarter, however, shares were still up 26.69% for the past year. Shares were 32.26% lower than their last high on June 15, 2026. The company’s stock has a quantitative Morningstar Rating of 3 stars.
Entain ENT
- Sector: Consumer Cyclical
- Industry: Gambling
- Economic Moat: Not Rated
Entain tumbled 23.95% in the third quarter, leaving shares down 50.51% for the past year. Stocks in the company were 54.11% below the last high on Sept. 30, 2025. Entain has a quantitative Morningstar Rating of 3 stars.
Games Workshop GAW
- Sector: Consumer Cyclical
- Industry: Leisure
- Economic Moat: Not Rated
Games Workshop slid 15.72% in the third quarter, while shares were still up 27.75% for the past year. Shares were 23.58% below their last high on June 25, 2026. The company’s stock has a quantitative Morningstar Rating of 3 stars.
Centrica CNA
- Sector: Utilities
- Industry: Utilities - Independent Power Producers
- Economic Moat: None
Centrica dropped 12.43% in the third quarter, leaving the stock down 8.65% for the past year. Shares were 32.96% lower than their last high on April 7, 2026. The company’s stock has a Morningstar Rating of 4 stars and trades at a 26% discount to the fair value estimate of £2.00.
Companies not formally covered by a Morningstar analyst are statistically matched to analyst-rated companies, allowing our models to calculate a quantitative star rating.
