
Targeting the Infrastructure Middle-Market Opportunity with Secondary Investing
- Strategy insight
May 1, 2025 | 8 min read
Historically the infrastructure asset class has been dominated by the largest, most established general partners (GPs). However, limited partners (LPs) can potentially increase risk-adjusted returns by capitalizing on the expanding infrastructure middle market,1 which similar to the longer-term trend across private equity, has on average, broadly outperformed the large-cap segment while also offering LPs enhanced liquidity.
Below, we examine infrastructure’s evolving middle-market GP landscape, explain why exposure to the middle market can be an important addition to an infrastructure portfolio, and share why we believe secondary investments offer one of the most effective ways to target this opportunity-rich segment while limiting downside risk.
The expanding infrastructure middle-market ecosystem
Private infrastructure is a large and dynamic market which has amassed the bulk of its more than $1.5 trillion AUM rapidly over the past decade.2 This rise has been largely driven by a small group of the largest and most tenured infrastructure GPs, which have attracted over 50% of the capital raised over the past five years.3 These established GPs rapidly expanded their flagship fund sizes (many exceeding $10 billion and some exceeding $20 billion) and added adjacent fund strategies with limited competition from new entrants.
The definition of infrastructure has expanded over the past decade in response to secular trends focused on changing demographics, government policy, advancing technology, and energy transition. With the broadening scope of what is considered infrastructure, there has been a proliferation of new GPs and new strategies launched by existing GPs. Most of these new GPs and strategies are targeting the middle market. Despite the historical capital raising dominance of the large-cap segment, infrastructure’s middle market represents a vast opportunity set accounting for nearly 95% of infrastructure’s transaction volume and over 90% of active GPs by count.4
Any meaningful analysis of the middle-market infrastructure landscape must include emerging managers and sector specialists. Emerging managers—those investing from their first or second fund (GP Strategy Fund I-II)—comprise over half of the middle-market infrastructure segment. This dominance stems from two trends: established managers (Fund III+) graduating to large-cap segments, and the recent surge of new GP entrants launching their initial strategies. Sector specialists have similarly captured the middle market, representing over half of all funds closed in the past five years.5 Power, renewables, energy transition, midstream, and digital infrastructure specialists particularly dominate the value-add segment and the North America GP landscape.
As illustrated in the chart below, mid-market GPs are accessing all segments across the expanding infrastructure landscape. The largest segment of GPs within infrastructure is core-plus, which we have divided below by geography between European and North American, and given the high percentage of emerging managers in North America, we have also delineated the established and emerging universe of GPs in the region. GPs in the core-plus segment are largely investing across a mix of sub-sectors into platform companies whose operating assets and predictable cash flows provide opportunities for value creation through operational improvements, selective development, and M&A. Additional segments include a handful of core strategies and a relatively nascent segment of strategies which include growth strategies investing in earlier stage and infrastructure-adjacent companies, shown in the chart as “Global new infra and asset light.”
Diversified sector strategies GP landscape
Source: Preqin and HarbourVest proprietary database of middle-market closed-end, commingled infrastructure funds with an OECD focus as of December 31, 2024. Excludes open-end funds, fund-of-funds, special purpose vehicles, and co-investment vehicles. Diversified strategies are broadly defined as funds investing in multiple broad infrastructure categories such as transport, digital, renewables, etc. Number of distinct GP fund strategies is based on the number of different strategies offered by a specific GP and not the number of individual funds offered by a GP. Bubble size represents approximate market size by capitalization.
There is also a growing number of sector specialists responding to the expanding infrastructure opportunity set. Sector specialization can allow middle-market GPs to drive value creation or market sophistication akin to a larger platform while targeting the opportunity-rich middle market. There are also some sector specialist GPs that employ a highly specialized direct operator model developing and managing assets such as data centers or power generation facilities. As displayed in the chart below, sector specialists span the full risk/return spectrum, from strategies investing in core infrastructure to asset light business models servicing infrastructure assets (shown as “Climate hybrid private equity and infrastructure” and “Climate technologies and emerging market segments” in the bubbles below.)
Sector specialist GP landscape
Source: Preqin and HarbourVest proprietary database of middle market closed-end, commingled infrastructure and private equity funds with an OECD focus as of December 31, 2024. Excludes open-end funds, fund-of-funds, special purpose vehicles, and co-investment vehicles. Specialist GPs are defined as those with over 80% of capital deployed into one sub-segment of infrastructure such as digital infrastructure. These would be classified as specialists even if they may invest across fiber, towers, and data centers. Number of distinct GP fund strategies is based on the number of different strategies offered by a specific GP and not the number of individual funds offered by a GP. Bubble size represents approximate market size by capitalization.
This array of middle-market specialist investment strategies is offering unique opportunities across sectors with innovative approaches, value creation strategies, and liquidity options that are differentiated from traditional infrastructure large-cap investments.
Performance and liquidity potential in infrastructure’s middle market
We believe infrastructure’s unique middle-market characteristics have helped drive its superior return potential and differentiated liquidity profile. As displayed in the charts below, the middle market has outperformed the large-cap segment on a return basis. Average IRRs for vintages between 2013 and 2022 have outperformed by 230 basis points and the top quartile has performed by 320 basis points. TVPIs have outperformed by 0.16x on average and for the top quartile. We believe outperformance in the middle market has been driven by the combination of better entry valuations due to its fragmented opportunity set, and more abundant levers for value creation available to smaller and less professionalized companies.
Infrastructure’s middle market stands up to large cap: alpha potential vs. stability
Net performance by fund size (2013 - 2022 vintages)
Source: HarbourVest proprietary data and Preqin data available as of December 31, 2024. Includes closed-end, commingled infrastructure funds with an OECD primary focus. Middle market represents funds with a final fund size between $200 million and $5 billion. Large cap represents funds with a final fund size of over $5 billion. Percentages represent the cutoffs for top quartile, median, and bottom quartile performers and the ● inside the box denotes the average of the dataset. Not representative of any HarbourVest fund, account, or experience. Past performance is not a guarantee of future results.
While mark-to-market performance is an important part of the story, distributions must also be considered. Our analysis looks at maturing infrastructure middle-market funds within four to seven years from inception that are in the early stages of exiting assets to highlight the impact of recent market volatility on liquidity and exits. Displayed in the chart below, on average, middle-market funds distributed twice as much to investors based on paid-in-capital compared to their larger peers at a similar stage of maturity. This illustrates how smaller companies can have greater options around paths to exit than large-cap companies, which are generally more reliant on capital markets, either directly through IPOs or indirectly with strategic and/or financial buyers that require support of large debt issuances.
Middle-market exit optionality supports greater liquidity relative to large caps
Realizations by fund size (2013 - 2022 vintages)
Source: HarbourVest proprietary data and Preqin data available as of December 31, 2024. Includes closed end, commingled infrastructure funds with an OECD primary focus. Middle market represents funds with a final fund size between $200 million and $5 billion. Large cap represents funds with a final fund size of over $5 billion. Not representative of any HarbourVest fund, account, or experience. Past performance is not a guarantee of future results.
Unlocking infrastructure’s middle market with secondaries
Infrastructure’s middle market can offer investors greater opportunity in terms of returns and liquidity but, as seen in the charts above, it also suffers from a wider dispersion of returns and lower bottom quartile potential. So, while the middle-market opportunity set is vast, accessing its alpha potential requires greater manager selection skill and deep market coverage.
- Avoiding blind pool uncertainty: A significant portion of middle-market managers fall into the category of emerging managers, which notably have shorter track records and less proven investment and operational execution capabilities. Secondary investing provides access to middle-market portfolios in pre-specified assets, mitigating blind pool risk and enabling visibility for investors into an emerging GP’s execution capabilities prior to investing.
- Improving diversification: Many middle-market strategies tend to be inherently less diversified due to their smaller scale and specialized focus on specific regions and sub-sectors. A diversified secondary offering, however, offers LPs access to a variety of specialist GPs through a single fund that covers numerous strategies across markets and sub-sectors, often providing exposure to 100+ underlying companies alongside 20 specialist and generalist GPs.
- Enhancing underwriting: The typical primary fund evaluation process, which often focuses on historical performance, is less effective for projecting and identifying future outperformance for emerging GPs and operations-oriented specialists with shorter track records. Investing through secondaries provides the opportunity to conduct a comprehensive evaluation of the fund manager’s current assets by underwriting unrealized portfolios and validating holding valuations.
- Harnessing current liquidity and price dynamics: Secondary investors can not only react to deal flow but also proactively create it based on market trends and asset quality, which can lead to optimized exposures and more attractive price points at entry. This is particularly relevant in a liquidity constrained environment, and the current backdrop is offering access to high-quality assets at prices that are typically below the fair market value of the underlying assets, leading to attractive risk-adjusted returns.
- Accessing portfolio winners: Portfolio companies often require additional capital to sustain their growth trajectory. Continuation vehicles and other GP-led transactions offer GPs a means to support the next stage of value creation and can provide secondary investors access to risk-mitigated, top-performing assets.
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Key takeaways
Middle-market deals can provide access to parts of the infrastructure market that are often difficult for larger GPs to penetrate, such as platform buildout strategies. And the middle market houses a high percentage of specialist GPs, offering the ability to rely on industry-specific expertise and established sourcing networks. However, engaging in this market requires a high amount of manager selection skill which can be challenging to accomplish when evaluating emerging managers with shorter track records or highly specialized strategies with unique market characteristics.
By tapping into the middle-market segment through secondary investments, investors can access seasoned assets, benefit from differentiated sourcing, and potentially earn premium returns with mitigated risks. We believe selecting a top secondary manager to access the middle market is paramount, as they have the expertise, resources, deep relationships, and flexibility to pursue and structure different transaction types.
- We define the middle market as funds with capitalizations between $200 million and $5 billion and companies with enterprise values (EVs) between $50 million and $2.0 billion.
- HarbourVest proprietary database and Preqin data available as of December 31, 2024.
- HarbourVest proprietary database and Preqin data available as of December 31, 2024. Data based on the 5-year period between 2019–2023.
- HarbourVest proprietary data and Preqin data available as of December 31, 2024. Includes closed-end, commingled infrastructure funds with an OECD primary focus. Middle market represents funds with a final fund size between $200 million and $5 billion. Large cap represents funds with a final fund size of over $5 billion.
- HarbourVest proprietary database and Preqin data available as of December 31, 2024. Data represents middle-market closed-end, commingled infrastructure funds with an OECD focus for the 5-year period 2019-2023. Excludes open-end funds, fund-of-funds, special purpose vehicles, and co-investment vehicles.
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Infrastructure Strategy Risks. Investments in infrastructure and real assets entail certain specific risks, including fluctuations of commodity prices, uncertainty of reserves, exploration and development risks, uncertainty in the developing alternative energy markets and technology, and governmental support and regulations. Infrastructure strategies may be exposed to substantial risk of loss from environmental claims arising in respect of its investments. Furthermore, changes in environmental laws or regulations or the environmental condition of an investment could create liabilities that did not exist at the time of its acquisition and that could not have been foreseen. Investments in natural resources and energy services companies, including mining and oilfield service, product manufacturing, and technology businesses that are involved in the preparation, drilling, completion, production, and abandonment of oil and gas wells and mines could be subject to fluctuations in the demand for their services based on commodity prices, the macroeconomic environment, customer concentration, availability of alternative technologies or services and political or market pressures favoring these alternatives. Environmental groups could protest about the development or operation of infrastructure assets, which might induce government action to the detriment of the Fund.
Secondary Investing Risk. Secondary market transactions may impose higher costs than other investments and may require a fund to assume contingent liabilities associated with events occurring prior to the Fund’s investment. The overall performance of an Underlying Portfolio Fund acquired through a secondary transaction will depend in large part on the purchase price paid. In addition, a fund will generally not have any ability to negotiate terms with respect to interests in Underlying Portfolio Funds invested in through secondary market transactions.