Pension Funds Explained

Pension funds are investment vehicles designed to fund retirement benefits for workers. They collect contributions from employers (and often employees), invest those contributions across a diversified portfolio, and use the accumulated wealth to pay benefits when participants retire. With over $35 trillion in global assets, pension funds are the largest category of institutional investor — bigger than hedge funds, sovereign wealth funds, and endowments combined.

Pension funds matter to markets because of their sheer scale and consistent presence. They are among the largest holders of stocks and bonds in every developed economy. Their investment decisions — shifting allocations, hiring and firing managers, entering new asset classes — ripple across the financial system. To understand how they fit within the broader institutional landscape, see our guide on institutional investors.

Defined Benefit vs. Defined Contribution Plans

The pension world divides into two fundamentally different structures, each with distinct implications for investment management and market behavior.

Defined Benefit Plans

A defined benefit (DB) plan promises participants a specific monthly retirement payment, typically calculated as a formula based on salary history and years of service. For example: 2% of final average salary multiplied by years of service. An employee who worked 30 years and earned a final average salary of $80,000 would receive $48,000 per year in retirement.

The employer bears all investment risk in a DB plan. If the fund's investments underperform, the employer must contribute additional capital to cover promised benefits. If investments outperform, the employer can reduce future contributions. This structure creates powerful incentives for DB plans to invest well — and serious consequences when they don't.

DB plans are the dominant form for public sector employees in the United States. State and local government workers — teachers, police, firefighters, municipal employees — are typically covered by large DB pension funds. The largest include CalPERS (California Public Employees' Retirement System), CalSTRS (California State Teachers' Retirement System), and the New York State Common Retirement Fund.

In the private sector, DB plans have been in steady decline since the 1980s. The financial burden of guaranteeing retirement payments, combined with accounting rule changes that forced companies to reflect pension obligations on their balance sheets, has driven most corporations to freeze or terminate their DB plans. Companies like IBM, General Electric, and Lockheed Martin have all transitioned away from DB plans.

Defined Contribution Plans

A defined contribution (DC) plan specifies contributions rather than benefits. The employer contributes a set percentage of salary (often matched by the employee), and the accumulated contributions plus investment returns determine the retirement benefit. The most common DC plan is the 401(k).

In a DC plan, investment risk shifts entirely to the employee. If the stock market drops 30% the year before someone retires, their retirement income drops accordingly. Employees typically choose from a menu of mutual funds and target-date funds offered by the plan, making their own asset allocation decisions.

DC plans now cover the majority of American private sector workers. Total assets in DC plans exceed $11 trillion in the U.S. alone. However, because DC plan assets are managed at the individual level (through providers like Fidelity, Vanguard, and TIAA), they don't appear as institutional investors in 13F filings the way DB plans do.

How Pension Funds Invest

Defined benefit pension funds are sophisticated institutional investors with large internal or external investment teams. Their investment approach is shaped by a unique constraint: they must generate sufficient returns to fund specific future liabilities.

Asset-Liability Management

The starting point for pension fund investing is asset-liability management (ALM). Unlike a hedge fund that simply tries to maximize returns, a pension fund must match its assets against a specific stream of future obligations — retirement payments stretching 30-50+ years into the future.

This liability-driven approach has several implications. Pension funds allocate heavily to fixed income because bonds provide predictable cash flows that can be matched against benefit payments. They invest in equities for growth to keep pace with rising benefit costs. And they diversify into alternatives — real estate, private equity, hedge funds, infrastructure — to enhance returns and reduce portfolio volatility.

Typical Asset Allocation

A representative pension fund portfolio in 2025 includes:

• Public equities: 30-50% — domestic and international stocks, managed through a mix of passive indexing and active management
• Fixed income: 20-35% — government bonds, corporate bonds, inflation-linked securities, and credit strategies
• Private equity: 5-15% — buyout funds, growth equity, and increasingly co-investments
• Real estate: 5-15% — core properties, value-add strategies, and real estate funds
• Hedge funds: 3-10% — diversifying strategies like global macro, relative value, and market neutral
• Infrastructure: 2-8% — roads, utilities, renewable energy, and transportation assets
• Cash and other: 1-5%

The trend over the past 20 years has been a steady shift away from bonds and toward alternatives. In 2000, a typical pension fund held 60% equities and 30% bonds with minimal alternatives. Today, alternatives represent 20-40% of many pension portfolios, driven by the search for higher returns in a historically low interest rate environment.

You can see the public equity portfolios of major pension funds on the HedgeTrace rankings page, which lists the largest filers by equity assets under management.

Major Pension Funds

Several pension funds are large enough to move markets and set trends for the industry.

CalPERS

The California Public Employees' Retirement System is the largest public pension fund in the United States, managing approximately $500 billion for 2 million members. CalPERS has been an influential force in corporate governance, pioneering the concept of shareholder activism by public pension funds. Its investment decisions — particularly moves to enter or exit asset classes — are closely watched as signals for the broader pension industry.

CalPERS files quarterly 13F reports with the SEC. You can track its U.S. equity holdings using the HedgeTrace fund search tool.

CalSTRS

The California State Teachers' Retirement System manages approximately $330 billion for California educators. CalSTRS has been a leader in sustainable investing, integrating environmental, social, and governance (ESG) factors into its investment process. Like CalPERS, its 13F filings are publicly available.

Canadian Pension Plans

Canada's major pension funds — Canada Pension Plan Investment Board (CPPIB), Ontario Teachers' Pension Plan (OTPP), and Caisse de depot et placement du Quebec (CDPQ) — are widely regarded as among the most sophisticated pension investors in the world. The "Canadian Model" emphasizes direct investing in private equity and infrastructure rather than allocating through external fund managers, significantly reducing fees.

CPPIB manages over $600 billion CAD and has become one of the largest direct investors in global infrastructure and private equity. Ontario Teachers' pioneered direct private equity investing by pension funds in the 1990s.

Japanese Government Pension Investment Fund

The GPIF is the largest pension fund in the world, managing approximately $1.6 trillion for Japan's public pension system. GPIF made headlines in 2014 when it dramatically shifted its allocation from predominantly Japanese government bonds to a more balanced portfolio with greater equity exposure. This single decision moved billions in capital across global markets.

The Pension Funding Crisis

Many defined benefit pension funds face a funding gap — their investment assets are insufficient to cover their promised future benefits. This challenge has intensified over recent decades.

Low interest rates were the primary culprit for many years. Pension liabilities are calculated using a discount rate — when interest rates are low, the present value of future obligations rises. A 1% drop in interest rates can increase a pension fund's liabilities by 10-15%, even if the actual benefit payments remain unchanged. While rates have risen since 2022, many funds locked in losses during the low-rate era.

Demographic shifts compound the problem. People are living longer, collecting benefits for more years, while the ratio of active workers to retirees shrinks. A plan designed when the average retiree collected benefits for 15 years now faces 25-30 years of payments.

Contribution shortfalls from government sponsors have worsened many public pension funds' positions. Politicians have incentives to defer pension contributions — the money can be spent on visible programs today while the consequences fall on future administrations. This chronic underfunding has left some public pension funds, like those in Illinois and Kentucky, with funded ratios below 50%.

The aggregate funding gap for U.S. state and local pension plans is estimated at $1-4 trillion, depending on the discount rate assumptions used. This gap influences pension fund investment behavior — pushing many toward higher-return (and higher-risk) asset classes in an attempt to close the shortfall.

Pension Funds and 13F Filings

Pension funds managing over $100 million in qualifying equity assets must file 13F reports with the SEC. These quarterly filings provide detailed disclosure of U.S. equity holdings, including position sizes and changes.

Pension fund 13F filings reveal several useful patterns for market observers:

Sector tilts — seeing whether pension funds are overweight or underweight specific sectors compared to the benchmark. A collective shift toward or away from a sector by pension funds can signal significant capital flows given their combined size.

Manager conviction — pension funds that actively manage portions of their equity portfolios reveal their stock picks through 13F filings. Large new positions or significant additions can indicate strong conviction.

Index changes — many pension funds index a large portion of their equity allocation. When major indices add or remove stocks, pension fund 13F filings reflect the mechanical buying and selling.

You can search for specific pension fund holdings, track quarterly changes, and compare portfolios using the HedgeTrace fund search. For a broader view of how pension fund holdings relate to other institutional investors, explore the HedgeTrace stock tool to see all institutional holders of a specific company.

Pension Funds as Hedge Fund Allocators

Pension funds are the largest source of capital for hedge funds, representing an estimated 25-30% of total hedge fund assets. Their allocation to hedge funds has grown steadily as pension funds searched for diversification and higher returns.

The relationship is not without controversy. Hedge fund fees — typically 1.5-2% management fees plus 15-20% performance fees — consume a significant portion of returns. Several large pension funds, including CalPERS, have reduced or eliminated their hedge fund allocations, arguing that the net-of-fee returns don't justify the complexity and cost. Others maintain substantial hedge fund programs, arguing that the diversification benefits warrant the fees.

Pension funds that allocate to hedge funds typically invest through a combination of direct allocations to large, established managers and fund of funds vehicles that provide diversified hedge fund exposure. You can compare the largest hedge funds that manage pension capital using our rankings page.

Pension Fund Trends

Several trends are reshaping pension fund investing.

Private market growth — pension funds continue to increase allocations to private equity, private credit, and infrastructure. The expected return premium over public markets and the reduced volatility from infrequent valuations make private assets attractive for long-horizon investors.

ESG integration — environmental, social, and governance factors are increasingly embedded in pension fund investment processes. European pension funds lead this trend, but U.S. public pension funds are also adopting ESG frameworks, driven by both fiduciary considerations and beneficiary expectations.

Fee pressure — pension funds are aggressively negotiating lower fees with external managers, consolidating manager rosters, and bringing more investment management in-house. The Canadian model of direct investing has inspired pension funds globally to build internal capabilities.

De-risking — as pension funds close to full funding, many are shifting toward "liability-driven investing" (LDI) strategies that more closely match assets to liabilities, reducing equity exposure in favor of long-duration bonds and interest rate derivatives.

Pension funds will remain the dominant institutional investor class for decades to come. Tracking their activity through 13F filings and tools like HedgeTrace provides valuable insight into the investment decisions of the world's largest pools of retirement capital.