Portfolio Construction: How to Build a Fund Strategy

Portfolio construction: How to develop a fund strategy

Author:

The Carta Team

Read time:

10 minutes

Published date:

March 9, 2026

Understand the process of portfolio construction for private funds, from developing an investment thesis to modeling the key levers that will define your fund's strategy.

What is portfolio construction?

Portfolio construction is the multi-step process of designing an investment strategy to achieve a fund's specific goals. It is the blueprint a general partner (GP) creates to select the right mix of investments that will balance portfolio risk and maximize returns for their investors, known as limited partners (LP). This process involves determining how to allocate assets to meet the fund's objectives within a defined risk tolerance and investment horizon. A thoughtful portfolio construction strategy (often referred to as simply your fund strategy) is critical to success.

Instead of simple security selection, you are architecting the entire investment vehicle from the ground up. Your portfolio construction model becomes the core of your pitch to LPs, demonstrating that you have a disciplined and well-reasoned plan for how you will invest their capital. It is the quantitative proof behind your qualitative story. It includes forecasts for:

For alternative investments in private funds, this concept takes on a unique meaning. For a venture capital (VC) or private equity (PE) manager, portfolio construction is about defining the fundamental parameters of the fund itself, including how much capital to raise, how many companies to back, and how to allocate that capital over the fund's multi-year lifespan. Your fund strategy should touch on the following elements:

How portfolio construction differs for private funds

While the goal of building a strong portfolio is universal, the construction of that portfolio in private funds operates under a completely different set of rules than in public markets. The nature of the assets, the availability of information, and the time horizons are fundamentally distinct. Understanding these differences is the first step to building a successful private fund strategy.

These differences are critical for fund managers to understand as they develop their strategy.
Dimension Public market investing Private market investing (VC/PE)
Liquidity High (assets can be bought or sold quickly) Capital is typically locked up for a fund lifespan of 10 to 12 years, with sponsors facing an average holding period of five years before they can exit all portfolio positions and fully return capital.
Data availability Abundant (real-time pricing, public financials) Scarce (private data, infrequent valuations)
Risk profile Market risk, volatility Execution risk, business failure
Return driver Diversification across asset classes The primary return driver for a VC fund is making concentrated bets on a few high-growth winners. The economics of this model mean that a single successful investment can be enough to return the entire fund. This potential for asymmetric returns is why VCs focus on finding outliers rather than a portfolio of modest successes.

The private fund portfolio construction process

For a new fund manager, understanding how to approach portfolio construction can feel overwhelming. The key is to break it down into a clear, step-by-step process. This structured approach can make the complex task feel more manageable and actionable, turning a daunting challenge into a series of logical decision-making steps.

Step 1: Develop an investment thesis

Every strong portfolio begins with a clear investment thesis. This is the fund's story and its unique point of view on the market, providing the discipline to guide every investment selection. It is the qualitative narrative that serves as the essential foundation upon which the quantitative fund model is built.

Step 2: Model the fund strategy

This step is where the investment thesis is translated into a financial model. Without a dedicated platform, managers have been forced to build these models in complex, error-prone spreadsheets. The process is especially difficult for active funds, where calculating the value of unrealized gains is tricky and lacks a widely accepted industry standard for how to value their investments.

Step 3: Execute and manage the portfolio

Once the fund is launched and capital is raised, the focus shifts from the initial construction to the ongoing execution and portfolio management. This involves deploying capital according to the plan, monitoring company performance, and handling all the operational duties of running a fund.

Step 4: Rebalancing your strategy

As part of your ongoing investment management, you may need to evolve and optimize your portfolio construction model as market conditions change. As you gain more visibility into your portfolio, set aside time to regularly evaluate whether or not your investments align with your original model to reach your fund’s financial goals.

Key levers of private fund portfolio construction

To compete with other funds, you need to be able to differentiate yourself while creating a plan that’s realistic and sustainable. Your fund strategy should align with your capabilities, network, market opportunities, and LP interests.

Fund size

Your fund size is your strategy. The size of your fund influences almost every element of your investment strategy: the number of companies in your portfolio, your check size, the amount of reserve capital you have, the LPs you attract, and the return profile for your fund.

Number of investments and target ownership

Once you’ve settled on a fund size, the next step is to outline the stage, sectors, and types of founders you’ll invest in.

Scenario modeling

Do a pricing model to map out your fund’s potential financial constraints and growth. What size investments do you plan to make? How many investments do you need to make over the course of a year to generate significant returns? What about over the life of the fund?

Follow-on strategy and reserve capital

Reserve capital is the portion of the fund set aside for future investments in existing portfolio companies, called follow-on investments.

Capital recycling

Capital recycling is the practice of reinvesting the proceeds from early exits back into new investments.

Explore alternative liquidity paths

Managing a portfolio over a decade-long fund life means that providing liquidity for your LPs is a constant strategic consideration. While traditional exits like IPOs or acquisitions are the primary goal, market conditions can shift.

From construction to management: Tracking fund performance

It's important to distinguish between portfolio construction and portfolio management. Portfolio construction is the plan you create before you invest, while portfolio management is the ongoing process of tracking your performance against that plan.

Building a defensible fund strategy with an integrated platform

A thoughtful portfolio construction plan is necessary, but it's not sufficient for success in today's competitive market. To truly build an institutional-grade firm, you need an integrated technology platform that connects your strategic model to your daily fund operations.