According to Bloomberg, Jefferies Group LLC reported that environmental, social, and governance (ESG) investment funds have increased their allowable exposure to nuclear energy and defense-related equities — a shift reflecting evolving investor definitions of sustainability and climate resilience.
Nuclear Allocation Rises to 12.4% Across ESG Funds
The Jefferies analysis found that the average nuclear energy exposure across global ESG-focused equity funds rose to 12.4% in Q1 2026, up from 8.7% in Q4 2025. This 3.7 percentage-point increase occurred over a single quarter and represents the largest quarterly jump since Jefferies began tracking the metric in 2022. The firm attributed the rise to revised ESG frameworks adopted by major index providers, including MSCI and FTSE Russell, which reclassified nuclear power as a low-carbon energy source in late 2025.
Defense Sector Access Expands Amid Geopolitical Reassessment
Jefferies noted that 62% of ESG funds tracked by its analysts now permit some level of defense sector exposure, compared with 44% in 2024. This change followed updated guidance from the European Federation of Financial Analysts Societies (EFFAS) in March 2026, which clarified that companies supplying dual-use technologies for civil nuclear safety or cyber-defense infrastructure may qualify under ESG criteria if aligned with UN Sustainable Development Goals 7 (Affordable and Clean Energy) and 16 (Peace, Justice and Strong Institutions). According to the report, 17 of the top 25 ESG ETFs by AUM now hold at least one defense contractor, including Raytheon Technologies and Lockheed Martin.
Regulatory and Index Provider Shifts Drive Reallocation
The European Union’s Sustainable Finance Disclosure Regulation (SFDR) Article 8 fund classification was updated in January 2026 to allow inclusion of nuclear generation assets meeting EUR 1 billion annual emissions threshold thresholds — a standard met by all EU-operated pressurized water reactors. Separately, MSCI announced on 15 February 2026 that it would remove its ‘controversial weapons’ exclusion for firms deriving less than 15% of revenue from non-conventional arms, provided those firms publish verified third-party human rights impact assessments annually. Jefferies estimates this policy change affected 23 publicly listed defense suppliers globally.
Practitioner Implications for Portfolio Construction
For supply chain professionals managing ESG-aligned capital allocations, these shifts signal material recalibration requirements. Nuclear energy investments increasingly involve long-lead procurement of reactor components — such as Zircaloy-4 fuel cladding tubes manufactured in France and Japan — requiring multi-year vendor qualification cycles. Similarly, defense-sector ESG eligibility now hinges on granular supply chain due diligence: Jefferies cites a 2025 audit of BAE Systems’ UK supply base that required Tier 2 and Tier 3 suppliers to submit ISO 20400-compliant sustainable procurement documentation for 98% of raw material line items. These developments raise compliance workload for ESG portfolio managers — particularly those overseeing funds with >€500 million in AUM — by an estimated 17 hours per quarter per fund, according to internal Jefferies operational benchmarks.
Source: Bloomberg
Compiled from international media by the SCI.AI editorial team.
