Private infrastructure debt is emerging as a distinct segment within institutional fixed income portfolios. It is more than a niche extension of corporate or real estate credit, offering a combination of resilience, stability, and favourable risk-adjusted returns. These characteristics are underpinned by the essential services provided by its underlying assets and the structural protections built into its contracts.

This white paper uses infraMetrics to examine how private infrastructure debt differs from standard corporate and real estate credit indices. It highlights key differences in credit stability, sector composition, performance behaviour, and benchmark alignment. The analysis compares infrastructure debt indices (both investment-grade and high-yield) with commonly used public benchmarks such as Bloomberg corporate (IG and HY), Markit iBoxx (IG and HY), Dow Jones Real Estate (IG and HY), and the Markit iBoxx “Infrastructure” HY index. We evaluate performance, credit behaviour, sector composition, drawdown characteristics, and benchmarking alignment over a full market cycle from 2014 to 2025.

Key findings from the analysis include:

• Robust credit performance: Infrastructure debt consistently exhibits lower default probabilities and higher recovery rates than public corporate bonds or real estate credit. infraMetrics data show that even non-investment-grade infrastructure loans exhibit strong capital preservation characteristics. Default risk is highest during early construction phases but drops significantly once projects become operational, reflecting the lifecycle de-risking unique to this asset class.

• Distinct sector allocation and cash flow dynamics: Infrastructure debt portfolios are heavily concentrated in essential service sectors (e.g. transport, energy, power, utilities), unlike corporate and real estate benchmarks that are dominated by cyclically sensitive sectors (financials, industrials, consumer, etc.). Infrastructure sectors generate regulated or long-term contracted revenues with low cyclicality, supporting more predictable cash flow profiles. This distinct sector mix results in materially different risk transmission and return behavior compared to traditional credit indices.

• Superior risk-return profile: infraMetrics indices have higher risk-adjusted returns over long-term horizons in both investment-grade and high-yield segments. For example, the infra100 Project NIG (non-investment grade) index shows the highest risk-return ratio among the indices evaluated, while maintaining a shorter duration and moderate yield. Overall, non-investment-grade infrastructure debt achieved lower volatility than traditional high-yield benchmarks, with comparable or better total returns over the analysis period.

• Resilience during market stress: During periods of economic dislocation—such as the 2015 and 2018 credit selloffs or the 2022 rate-driven bond market correction—corporate and real estate credit indices suffered sharp, prolonged drawdowns. In contrast, infraMetrics indices showed smaller, shorter-lived declines, reflecting their reduced sensitivity to macroeconomic shocks and policy tightening. This pattern of lower drawdown and quicker recovery supports the case for infrastructure debt as a reliable anchor in credit portfolios.

• Benchmarking inadequacies of using listed indices: Standard public benchmarks fail to reflect the underlying reality of private infrastructure debt. Sector misalignment, absence of project finance instruments, and divergence in performance behavior render indices like from corporate bond market or real estate bond unsuitable for LPs and GPs managing infrastructure credit strategies. infraMetrics indices provide a purpose-built benchmarking framework calibrated to the actual characteristics of the asset class, enabling better strategy design, performance attribution, and investment decision-making.

This white paper illustrates that private infrastructure debt is not merely a risk-reduced subset of high-yield or real estate credit but an asset class in its own right, defined by contractual resilience, lifecycle de-risking, and economic fundamentals offering investors access to stable long-term income, downside protection, and efficient portfolio diversification. These qualities position infrastructure debt as a foundational element of modern institutional fixed income strategy.

Given its distinct risk-return profile, sector composition, cash flow dynamics, and response to economic shocks, infrastructure debt cannot be appropriately measured or managed using traditional credit benchmarks. Generic corporate bond or real estate indices fail to reflect the underlying characteristics of this asset class omitting essential services, misrepresenting volatility, and excluding project-level instruments. As a result, they distort performance attribution, risk assessment, and strategic allocation. The infraMetrics indices provide a fit-for-purpose alternative: a dedicated benchmarking framework built from real-world, asset-level infrastructure transactions, offering both LPs and GPs the tools to align investment analysis with the true nature of infrastructure credit. This tailored benchmark approach is essential for unlocking the full strategic potential of infrastructure debt in institutional portfolios.